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1.
Lyons, John.
A Novel Model for Fracture Acidizing with Important Thermal Effects.
Degree: 2013, Texas Digital Library
URL: http://hdl.handle.net/1969; 
http://hdl.handle.net/2249.1/66577
► Fracture acidizing is a well stimulation technique used to improve the productivity of low-permeability reservoirs, and to bypass deep formation damage. The reaction of injected…
(more)
▼ Fracture acidizing is a well stimulation technique used to improve the productivity of low-permeability reservoirs, and to bypass deep formation damage. The reaction of injected acid with the rock matrix forms etched channels (that depend on injection rate, mass transport properties, formation mineralogy, reaction chemistry of the acid, and temperature) through which oil and gas can then flow upon production.
The use of a model that can effectively describe
fracture acidizing is an essential step in designing an efficient and economical treatment. Several studies have been conducted on modeling
fracture acidizing, however, most of these studies have not accounted for the effect of variation in acid temperature (by heat exchange with the formation and the heat generated by acid reaction with the rock) on reaction rate and mass transfer of acid inside the
fracture.
In this study, a new
fracture acidizing model is presented that uses the lattice Boltzmann method for fluid transport and takes into account these temperature effects. The lattice Boltzmann method incorporates both accurate hydrodynamics and reaction kinetics at the solid-liquid interface. This method is also well known for its capability to handle re- active transport in complex geometries. This enables the method to model realistic
fracture shapes, on a pore-scale level, and predict the shape of the
fracture after acidizing. Results of carbonate
fracture dissolution with and without the thermal effects are presented. It is found that including thermal effects alters the predicted shape of the
fracture after acidizing.
Advisors/Committee Members: Nasr-El-Din, Hisham (advisor).
Subjects/Keywords: Fracture
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APA (6th Edition):
Lyons, J. (2013). A Novel Model for Fracture Acidizing with Important Thermal Effects. (Thesis). Texas Digital Library. Retrieved from http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66577
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lyons, John. “A Novel Model for Fracture Acidizing with Important Thermal Effects.” 2013. Thesis, Texas Digital Library. Accessed February 17, 2020.
http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66577.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lyons, John. “A Novel Model for Fracture Acidizing with Important Thermal Effects.” 2013. Web. 17 Feb 2020.
Vancouver:
Lyons J. A Novel Model for Fracture Acidizing with Important Thermal Effects. [Internet] [Thesis]. Texas Digital Library; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66577.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lyons J. A Novel Model for Fracture Acidizing with Important Thermal Effects. [Thesis]. Texas Digital Library; 2013. Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66577
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
2.
Grantab, Rassin.
Computational Studies of Fracture in Micro- and Nano-Scale
Structures.
Degree: PhD, Solid Mechanics, 2012, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:297637/
► The electronics industry drives a great deal of research towards inventing methods for creating smaller devices. In order for the current trend of the diminishing…
(more)
▼ The electronics industry drives a great deal of
research towards inventing methods for creating smaller devices. In
order for the current trend of the diminishing size of electronic
devices - such as cell phones and laptops - to continue, two main
breakthroughs are necessary: firstly, the electronic components
themselves must become smaller without a loss of computing power;
and secondly, the batteries that store the energy for these devices
must also become smaller without a loss of capacity. Semiconductor
nanowires and graphene present promising solutions for making
smaller electronic circuits, while lithium-ion batteries are
currently the most space-efficient energy-storage device. In order
for nanowires, graphene, and lithium-ion batteries to gain
widespread use, both their performance and reliability are of
paramount importance. Despite the fact that these nano- and
micro-scale structures are not directly under mechanical loads,
their reliability is still largely dictated by mechanical failure
during use, and therefore must be well-understood. To this end, the
work presented herein describes detailed analyses of
fracture and
failure in these small-scale structures. At the nanoscale,
fracture
in faceted semiconductor nanowires and graphene sheets containing
grain boundaries has been studied using molecular dynamics
techniques. Interestingly, the results of the molecular dynamics
simulations of the nanowires can easily be explained using
continuum
fracture mechanics, while the results of the graphene
sheets with grain boundaries are in complete discord with continuum
theories and general intuition. In the case of the lithium-ion
batteries, finite element simulations of crack propagation in
electrodes have been used to understand how initial defects grow in
graphite and silicon electrode particles during battery charging
and use.
Advisors/Committee Members: Shenoy, Vivek (Director), Guduru, Pradeep (Reader), Sheldon, Brian (Reader).
Subjects/Keywords: fracture
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APA (6th Edition):
Grantab, R. (2012). Computational Studies of Fracture in Micro- and Nano-Scale
Structures. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:297637/
Chicago Manual of Style (16th Edition):
Grantab, Rassin. “Computational Studies of Fracture in Micro- and Nano-Scale
Structures.” 2012. Doctoral Dissertation, Brown University. Accessed February 17, 2020.
https://repository.library.brown.edu/studio/item/bdr:297637/.
MLA Handbook (7th Edition):
Grantab, Rassin. “Computational Studies of Fracture in Micro- and Nano-Scale
Structures.” 2012. Web. 17 Feb 2020.
Vancouver:
Grantab R. Computational Studies of Fracture in Micro- and Nano-Scale
Structures. [Internet] [Doctoral dissertation]. Brown University; 2012. [cited 2020 Feb 17].
Available from: https://repository.library.brown.edu/studio/item/bdr:297637/.
Council of Science Editors:
Grantab R. Computational Studies of Fracture in Micro- and Nano-Scale
Structures. [Doctoral Dissertation]. Brown University; 2012. Available from: https://repository.library.brown.edu/studio/item/bdr:297637/
3.
Olarnrithinun, Sutee.
Discrete Dislocation Modeling of Fracture/Fatigue.
Degree: PhD, Solid Mechanics, 2013, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:320484/
► The discrete dislocation (DD) plasticity is truly mechanism-based plasticity and well-suited for mesoscale modeling in metal. The effects of size-dependent plasticity and plastic dissipation emerge…
(more)
▼ The discrete dislocation (DD) plasticity is truly
mechanism-based plasticity and well-suited for mesoscale modeling
in metal. The effects of size-dependent plasticity and plastic
dissipation emerge naturally from this framework.
The micromechanics of
fracture is material dependent and
involves a broad range of length and time scales. The intermediate
situation between the cleavage crack growth and the plastic
dissipation involved in
fracture based on DD plasticity is focused
here.
Fracture crack growth is affected by dislocations: (i)
dislocation motion shields the crack tip and increases the
dissipation energy and (ii) the local stress concentration
associated with discrete dislocation in the vicinity of the crack
tip can reach atomic bond strength, causing the crack to grow.
In this work fatigue crack growth from small cracked particle
into single crystal is first investigated with a focus on the
effects of plastic confinement due to elastic particle, and elastic
modulus mismatch between the reinforcement and matrix phases.
The results show that fatigue crack growth from micron-scale
particles is strongly influenced by size effect of plasticity,
elastic mismatch, and the presence of particle to plastic flow.
However the yield stress of the matrix material and the
cohesive strength in the cohesive zone model are unrealistic due to
the limitations of the standard DD algorithm.
Also the computational cost and storage can be reduced by
using symmetric boundaries.
Therefore the new algorithm of discrete dislocation
plasticity to improve the computational efficiency and its
application in the short crack problem are presented here.
To study the role of plastic anisotropy on crack growth in a
single crystal, the standard DD formulation can be extended to
perform the effects of plastic dissipation and dislocation/crack
interaction on the basal cleavage in HCP-like material.
To do so, the concept of plastic flow controlled by a Peierls
stress is first implemented to the standard DD methodology. The
results show that the
fracture toughness is largely independent of
plastic anisotropy.
Interestingly, the
fracture toughnesses of both Peierls
stress-controlled flow material and obstacle-controlled flow
material are unified through the new Stress Gradient Plasticity
concept.
Advisors/Committee Members: Curtin, William (Director), Blume, Janet (Reader), Padture, Nitin (Reader).
Subjects/Keywords: Fracture
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APA (6th Edition):
Olarnrithinun, S. (2013). Discrete Dislocation Modeling of Fracture/Fatigue. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:320484/
Chicago Manual of Style (16th Edition):
Olarnrithinun, Sutee. “Discrete Dislocation Modeling of Fracture/Fatigue.” 2013. Doctoral Dissertation, Brown University. Accessed February 17, 2020.
https://repository.library.brown.edu/studio/item/bdr:320484/.
MLA Handbook (7th Edition):
Olarnrithinun, Sutee. “Discrete Dislocation Modeling of Fracture/Fatigue.” 2013. Web. 17 Feb 2020.
Vancouver:
Olarnrithinun S. Discrete Dislocation Modeling of Fracture/Fatigue. [Internet] [Doctoral dissertation]. Brown University; 2013. [cited 2020 Feb 17].
Available from: https://repository.library.brown.edu/studio/item/bdr:320484/.
Council of Science Editors:
Olarnrithinun S. Discrete Dislocation Modeling of Fracture/Fatigue. [Doctoral Dissertation]. Brown University; 2013. Available from: https://repository.library.brown.edu/studio/item/bdr:320484/
Wake Forest University
4.
PATALAK, JOHN.
Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes.
Degree: 2017, Wake Forest University
URL: http://hdl.handle.net/10339/89875
Motor vehicle crashes (MVCs) of passenger vehicles are commonly cited and reported in published literature as a leading cause of death and injury. Similarly, in motorsports, on-track crashes are the leading cause of driver injury.
Subjects/Keywords: fracture
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APA (6th Edition):
PATALAK, J. (2017). Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes. (Thesis). Wake Forest University. Retrieved from http://hdl.handle.net/10339/89875
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
PATALAK, JOHN. “Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes.” 2017. Thesis, Wake Forest University. Accessed February 17, 2020.
http://hdl.handle.net/10339/89875.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
PATALAK, JOHN. “Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes.” 2017. Web. 17 Feb 2020.
Vancouver:
PATALAK J. Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes. [Internet] [Thesis]. Wake Forest University; 2017. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/10339/89875.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
PATALAK J. Evaluation of Lower Extremity Injury Mitigation and Investigation of Thoracolumbar Loading of Restrained Occupants During Frontal Crashes. [Thesis]. Wake Forest University; 2017. Available from: http://hdl.handle.net/10339/89875
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Oregon State University
5.
Semrick, Kalin.
Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites.
Degree: MS, Wood Science, 2012, Oregon State University
URL: http://hdl.handle.net/1957/30261
► The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the fracture toughness of low and high density polyethylene and…
(more)
▼ The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the
fracture toughness of low and high density polyethylene and wood plastic composites. A test fixture was developed to capture normal and tangential cutting forces at variable depth and rake angle. A tool interface method (TIM) is proposed to separate forces on both sides of the tool from the energy needed to propagate the crack. Also investigated were shear plane models of chip failure, which seek to measure toughness by modeling internal stresses in the chip. These results are compared to current methods of determining essential work of
fracture (EWF). It is found that cutting requires much less energy than current methods of EWF. Further work is suggested to better parameterize failure.
Advisors/Committee Members: Nairn, John (advisor), Kruzic, Jamie (committee member).
Subjects/Keywords: Fracture; Plastic-impregnated wood – Fracture
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APA (6th Edition):
Semrick, K. (2012). Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/30261
Chicago Manual of Style (16th Edition):
Semrick, Kalin. “Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites.” 2012. Masters Thesis, Oregon State University. Accessed February 17, 2020.
http://hdl.handle.net/1957/30261.
MLA Handbook (7th Edition):
Semrick, Kalin. “Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites.” 2012. Web. 17 Feb 2020.
Vancouver:
Semrick K. Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites. [Internet] [Masters thesis]. Oregon State University; 2012. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1957/30261.
Council of Science Editors:
Semrick K. Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites. [Masters Thesis]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/30261
University of Alberta
6.
Zhang, Lei.
Three-dimensional Numerical Models of Drilling Induced Core
Fractures.
Degree: MS, Department of Electrical and Computer
Engineering, 2011, University of Alberta
URL: https://era.library.ualberta.ca/files/p2676w188
► Drilling-induced fractures in borehole cores have distinct morphologies (e.g., petal, petal-centreline, saddle, and disk) and are produced under pure tensional stress, although most in-situ stresses…
(more)
▼ Drilling-induced fractures in borehole cores have
distinct morphologies (e.g., petal, petal-centreline, saddle, and
disk) and are produced under pure tensional stress, although most
in-situ stresses are compressive. 3D numerical models show that
tensile stress concentrations occur near the bottom of a vertical
borehole. A new algorithm is developed to trace 3D tensile
fractures for a range of crustal stress conditions. In a normal
fault regime, fractures change from petal/petal-centreline to
saddle to disk with increasing minimum horizontal stress (Sh). In a
strike-slip regime, saddle fractures occur, except where Sh is much
less than the vertical stress and petal centre-line fractures are
found. In a thrust fault regime, saddle and disk fractures occur at
low and high Sh, respectively. The results demonstrate that in-situ
stress is the dominant control on fracture morphology; variations
in Poisson’s ratio and core stub length primarily affect the
magnitude of tensile stress.
Subjects/Keywords: core fracture
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APA (6th Edition):
Zhang, L. (2011). Three-dimensional Numerical Models of Drilling Induced Core
Fractures. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/p2676w188
Chicago Manual of Style (16th Edition):
Zhang, Lei. “Three-dimensional Numerical Models of Drilling Induced Core
Fractures.” 2011. Masters Thesis, University of Alberta. Accessed February 17, 2020.
https://era.library.ualberta.ca/files/p2676w188.
MLA Handbook (7th Edition):
Zhang, Lei. “Three-dimensional Numerical Models of Drilling Induced Core
Fractures.” 2011. Web. 17 Feb 2020.
Vancouver:
Zhang L. Three-dimensional Numerical Models of Drilling Induced Core
Fractures. [Internet] [Masters thesis]. University of Alberta; 2011. [cited 2020 Feb 17].
Available from: https://era.library.ualberta.ca/files/p2676w188.
Council of Science Editors:
Zhang L. Three-dimensional Numerical Models of Drilling Induced Core
Fractures. [Masters Thesis]. University of Alberta; 2011. Available from: https://era.library.ualberta.ca/files/p2676w188
Texas A&M University
7.
Kim, Tae Hyung.
Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2570
► Determining fracture characteristics at the laboratory scale is a major challenge. It is known that fracture characteristics are scale dependent; as such, the minimum sample…
(more)
▼ Determining
fracture characteristics at the laboratory scale is a major challenge. It is
known that
fracture characteristics are scale dependent; as such, the minimum sample
size should be deduced in order to scale to reservoir dimensions. The main factor
affecting mechanical and hydrological characteristics of natural fractures is aperture
distribution, which is a function of scale and confining pressure, rather than roughness
of one
fracture surface. Scale and pressure dependencies of artificial and natural
fractures were investigated in this study using an X-Ray CT Scanner. Fractal dimension,
D, and amplitude parameter, A, of
fracture aperture approaches a constant value with
increased sampling area, similar to the behavior of
fracture roughness. In addition, both
parameters differ under different confining pressures for a reference sampling area.
Mechanical properties of
fracture-fracture deformation behavior and
fracture normal
stiffness were obtained from CT scan data as well.
Matrix porosity is relatively easy to measure and estimate compared to
fracture
porosity. On the other hand,
fracture porosity is highly heterogeneous and very difficult to measure and estimate. When matrix porosity of naturally fractured reservoirs (NFR)
is negligible, it is very important to know
fracture porosity to evaluate reservoir
performance. Since
fracture porosity is highly uncertain, fractal discrete fractal network
(FDFN) generation codes were developed to estimate
fracture porosity. To reflect scale
dependent characteristics of
fracture networks, fractal theories are adopted. FDFN
modeling technique enables the systematic use of data obtained from image log and
core analysis for estimating
fracture porosity. As a result, each
fracture has its own
fracture aperture distribution, so that generated FDFN are similar to actual
fracture
systems. The results of this research will contribute to properly evaluating the
fracture
porosity of NFR where matrix porosity is negligible.
Advisors/Committee Members: Schechter, David S. (advisor), Blasingame, Thomas A. (committee member), Keyser, John (committee member), Wattenbarger, Robert A. (committee member).
Subjects/Keywords: fracture; fractal
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APA (6th Edition):
Kim, T. H. (2009). Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2570
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kim, Tae Hyung. “Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models.” 2009. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/ETD-TAMU-2570.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kim, Tae Hyung. “Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models.” 2009. Web. 17 Feb 2020.
Vancouver:
Kim TH. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2570.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kim TH. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2570
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Hong Kong
8.
鍾培言.; Cheung, Pui-yin, Jason.
Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques.
Degree: Master of Medical Sciences, 2012, University of Hong Kong
URL: Cheung,
P.
J.
[鍾培言].
(2012).
Biomechanical
comparative
study
of
the
JuggerKnotTM
soft
anchor
technique
with
other
common
mallet
finger
fracture
fixation
techniques.
(Thesis).
University
of
Hong
Kong,
Pokfulam,
Hong
Kong
SAR.
Retrieved
from
http://dx.doi.org/10.5353/th_b4827389
;
http://dx.doi.org/10.5353/th_b4827389
;
http://hdl.handle.net/10722/173866
► Introduction Mallet finger is a common injury involving either an extensor tendon rupture at its insertion or an avulsion fracture involving the insertion of the…
(more)
▼ Introduction
Mallet finger is a common injury
involving either an extensor tendon rupture at its insertion or an
avulsion fracture involving the insertion of the terminal extensor
tendon. It is usually caused by a forceful blow to the tip of the
finger causing sudden flexion or a hyperextension injury. Fracture
at the dorsal aspect of the base of the distal phalanx is commonly
associated with palmar subluxation of the distal phalanx. Most
mallet finger injuries are recommended to be treated with
immobilization of the distal interphalangeal joint in extension by
splints. However, surgical fixation is still indicated in certain
conditions such as open injuries, avulsion fracture involving at
least one third of the articular surface with or without palmar
subluxation of the distal phalanx and also failed splinting
treatment. This study was designed to identify the strongest peak
load resistance among four mallet finger fracture fixation methods,
namely Kirschner wire fixation, pull-out wire fixation,
tension-band wire fixation and the JuggerKnot? (Biomet) soft anchor
fixation and to assess the role of the JuggerKnot? technique in
mallet finger fixation.
Materials and method
Four different
fixation techniques were assigned among twenty-four specimens (all
fingers, no thumbs) from six cadaveric human hands in a randomized
block fashion. Only one technique was performed on each finger. A
downward load was applied to flex the distal phalanx and the
maximum loading force was recorded. The load was tested at 30
degrees, 45 degrees and 60 degrees of flexion of the distal
interphalangeal joint. Two separate data sets were performed for
each finger before and after the osteotomy and fixation. The data
underwent Shapiro-Wilk normality testing before analysis. The
values of the mean peak load of the four groups were compared using
the one-way analysis of variance test in SPSS version 19.0.
Result
All data points passed the Shapiro-Wilk test for
normality. The mean peak load of the tension-band wiring group was
67.8N at 60 degrees of flexion which was significantly higher than
the other three groups (p=0.008). The JuggerKnot? fixation had mean
peak loads of 13.35N (30°), 22.51N (45°) and 32.96N (60°) which
were all above the required load for mobilization. No complications
of implant failure or fragmentation of the dorsal fragment was
noted.
Discussion
The tension-band wire fixation was the
strongest fixation method among the four. However it was cumbersome
and it had the most soft tissue trauma among the four. No major
difficulty was encountered during the testing. No fragmentation of
the dorsal fragment was encountered during the procedures. The
JuggerKnot? soft anchor fixation was a simple and easy technique
and did not require trans-articular Kirschner wire fixation for
protection. It could reduce and immobilize a grossly displaced
dorsal fragment easily and allowed for safe immediate mobilization
of the joint after operation as indicated by the peak load results.
This fixation technique was a viable…
Subjects/Keywords: Fracture fixation.
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APA ·
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Manager
APA (6th Edition):
鍾培言.; Cheung, Pui-yin, J. (2012). Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques. (Masters Thesis). University of Hong Kong. Retrieved from Cheung, P. J. [鍾培言]. (2012). Biomechanical comparative study of the JuggerKnotTM soft anchor technique with other common mallet finger fracture fixation techniques. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4827389 ; http://dx.doi.org/10.5353/th_b4827389 ; http://hdl.handle.net/10722/173866
Chicago Manual of Style (16th Edition):
鍾培言.; Cheung, Pui-yin, Jason. “Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques.” 2012. Masters Thesis, University of Hong Kong. Accessed February 17, 2020.
Cheung, P. J. [鍾培言]. (2012). Biomechanical comparative study of the JuggerKnotTM soft anchor technique with other common mallet finger fracture fixation techniques. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4827389 ; http://dx.doi.org/10.5353/th_b4827389 ; http://hdl.handle.net/10722/173866.
MLA Handbook (7th Edition):
鍾培言.; Cheung, Pui-yin, Jason. “Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques.” 2012. Web. 17 Feb 2020.
Vancouver:
鍾培言.; Cheung, Pui-yin J. Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques. [Internet] [Masters thesis]. University of Hong Kong; 2012. [cited 2020 Feb 17].
Available from: Cheung, P. J. [鍾培言]. (2012). Biomechanical comparative study of the JuggerKnotTM soft anchor technique with other common mallet finger fracture fixation techniques. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4827389 ; http://dx.doi.org/10.5353/th_b4827389 ; http://hdl.handle.net/10722/173866.
Council of Science Editors:
鍾培言.; Cheung, Pui-yin J. Biomechanical comparative study of the JuggerKnotTM soft
anchor technique with other common mallet finger fracture
fixationtechniques. [Masters Thesis]. University of Hong Kong; 2012. Available from: Cheung, P. J. [鍾培言]. (2012). Biomechanical comparative study of the JuggerKnotTM soft anchor technique with other common mallet finger fracture fixation techniques. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4827389 ; http://dx.doi.org/10.5353/th_b4827389 ; http://hdl.handle.net/10722/173866
9.
Underwood, Jarrod.
Acid Fracture and Fracture Conductivity Study of Field Rock Samples.
Degree: 2013, Texas Digital Library
URL: http://hdl.handle.net/1969;
http://hdl.handle.net/2249.1/66584
► Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of…
(more)
▼ Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of acid interaction on specific rock samples can be studied experimentally. Acid injection data and
fracture conductivity measurements obtained in the research presented in this thesis yielded results that qualified and quantified the impact of a specific acid system on rock samples of varying acid solubility.
Six rock samples from a carbonate reservoir were labeled A through F to protect proprietary information included in this research. A 2% potassium chloride solution was used for the acid system and
fracture conductivity measurements to prevent clay swelling. Injection temperature, contact time, and injection rate were designed to simulate field treatment conditions. The effects of a chelating agent on
fracture conductivity were also studied.
Before and after images of the rock samples indicated that the effect of 15% hydrochloric acid on the samples was limited but correlated with the rock acid solubility. Samples E and F had a greater value of acid solubility and showed noticeable surface etching. Samples A, B, and C had lower values of acid solubility and did not show signs of surface etching. Sample D was of moderate acid solubility and showed minimal signs of surface etching.
Fracture conductivity did not correlate directly with acid solubility, but likely was a function of inherent matrix permeability based on leak-off measurements and
fracture conductivity measurements. Finally, the
fracture conductivity of Sample D increased after exposure to a chelating agent.
Commonly, acid
fracture experimental studies are carried out with outcrop rock samples. The samples have more homogenous properties and without hydrocarbon content. In this study, cores from downhole formation were used. The original condition was preserved as much as possible to simulate real field situations. However, using field rock samples does present challenges not generally associated with outcrop rock samples.
Based on the information gathered from the work presented in this thesis, conclusions were drawn concerning the effectiveness of a 15% hydrochloric acid treatment in this formation and the challenges of using field rock samples.
Advisors/Committee Members: Zhu, Ding (advisor).
Subjects/Keywords: Acid Fracture
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APA (6th Edition):
Underwood, J. (2013). Acid Fracture and Fracture Conductivity Study of Field Rock Samples. (Thesis). Texas Digital Library. Retrieved from http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66584
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Underwood, Jarrod. “Acid Fracture and Fracture Conductivity Study of Field Rock Samples.” 2013. Thesis, Texas Digital Library. Accessed February 17, 2020.
http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Underwood, Jarrod. “Acid Fracture and Fracture Conductivity Study of Field Rock Samples.” 2013. Web. 17 Feb 2020.
Vancouver:
Underwood J. Acid Fracture and Fracture Conductivity Study of Field Rock Samples. [Internet] [Thesis]. Texas Digital Library; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Underwood J. Acid Fracture and Fracture Conductivity Study of Field Rock Samples. [Thesis]. Texas Digital Library; 2013. Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66584
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
10.
Catoor, Dhiraj.
Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling.
Degree: PhD, Division of Engineering. Materials Science
Engineering, 2008, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:58/
► In polycrystalline materials where transgranular cleavage is the preferred fracture mode, the crystallographic misorientation of fracture planes across grain boundaries can provide resistance to crack…
(more)
▼ In polycrystalline materials where transgranular
cleavage is the preferred
fracture mode, the crystallographic
misorientation of
fracture planes across grain boundaries can
provide resistance to crack growth, though the details of its
contribution to
fracture resistance is not fully understood. Recent
studies on diverse structural materials such as steels, aluminum
alloys and intermetallics show a correlation between an increased
fracture resistance and the twist component of grain
misorientation; however the lack of control over the degree and
type of misorientation has precluded a systematic analysis of the
problem. In this dessertation, this phenomenon is investigated
through in situ crack propagation experiments across grain
boundaries of controlled twist misorientation in bicrystals of
zinc. The lack of comprehensive understanding of the
micromechanisms of
fracture in single crystals of zinc required in
situ experiments to be initially conducted to investigate crack
propagation on the basal planes. In single crystals, quasistatic
loading caused crack propagation in short bursts of dynamic crack
extension followed by periods of arrests. In situ observations
confirmed re-nucleation of micro-cracks on parallel basal planes
and failure of the linking ligaments and crack-growth resistance
due to pre-existing twins in the crack path. The crack growth
response, load-displacement behavior and
fracture surface
topography were all found to be dependent on the crack propagation
direction on the basal plane. Significant resistance to crack
propagation was observed in bicrystals at the grain boundaries
through extrinsic toughening mechanisms that come into play upon
crack stagnation at the boundary. Strong dependence of the load
displacement behavior and crack propagation resistance on the twist
angle was observed. Several accommodation mechanisms such as
twinning in the crack-wake, strain localization and slip band
blocking contribute to
fracture resistance and suppress crack
propagation across grain boundary at higher twist angles.
Three-dimensional finite element models incorporating crystal
plasticity are used to explain the micromechanisms of crack
propagation, orientation-dependent crack growth response and
fracture surface topography in single crystals, and qualitatively
capture several features of crack-grain boundary interaction in
bicrystals.
Advisors/Committee Members: Kumar, Sharvan (director), Bower, Allan (reader), Briant, Clyde (reader), Curtin, William (reader).
Subjects/Keywords: Fracture
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APA (6th Edition):
Catoor, D. (2008). Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:58/
Chicago Manual of Style (16th Edition):
Catoor, Dhiraj. “Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling.” 2008. Doctoral Dissertation, Brown University. Accessed February 17, 2020.
https://repository.library.brown.edu/studio/item/bdr:58/.
MLA Handbook (7th Edition):
Catoor, Dhiraj. “Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling.” 2008. Web. 17 Feb 2020.
Vancouver:
Catoor D. Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling. [Internet] [Doctoral dissertation]. Brown University; 2008. [cited 2020 Feb 17].
Available from: https://repository.library.brown.edu/studio/item/bdr:58/.
Council of Science Editors:
Catoor D. Fracture in Single and Bicrystals of Zinc: Experiments and
Computational Modeling. [Doctoral Dissertation]. Brown University; 2008. Available from: https://repository.library.brown.edu/studio/item/bdr:58/
Louisiana State University
11.
Sprinkle, Saybl Beauton.
Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone.
Degree: MS, Veterinary Medicine, 2011, Louisiana State University
URL: etd-07072011-192636
;
https://digitalcommons.lsu.edu/gradschool_theses/729
► Objective -To compare the compression produced in reduction of experimentally created medial condylar fractures using lag screw fixation with medial vs. lateral approach, and to…
(more)
▼ Objective -To compare the compression produced in reduction of experimentally created medial condylar fractures using lag screw fixation with medial vs. lateral approach, and to determine the maximum torque at screw failure. Materials and Methods- Twelve (12) pairs (left and right) 3rd metacarpal bones (MC3) were collected from adult (2-7 years) Thoroughbreds euthanized for reasons unrelated to orthopedic disease. Complete parasagittal medial condylar osteotomies were created at a measurement of 9, 13, and 21 mm axial to the epicondylar fossa on four pairs each of cadaveric MC3 bones resulting in fracture fragments measuring 8, 12, and 20 mm in thickness. For each pair of cadaveric MC3, a lateral or medial approach was randomly selected to repair the condylar fracture using a single 4.5 mm AO cortical screw. Each repair was tested for fracture plane compression and screw torque to failure. Results-There was no significant difference in compression between the medial and lateral approaches for the 8 or 12-mm fragment groups. There was significantly more compression generated in the lateral approach when compared to the medial approach for the 20-mm fragment group. Failure occurred at significantly lower torque in the 8-mm group. There was no significant difference between medial and lateral approach in torque to failure for the 12 and 20-mm groups. Conclusion-Based on this data we have concluded that there was no significant difference in torque to failure between a medial vs. lateral approach for the 12 mm fragments but there was a significant difference for the 8 mm fragments and that a lateral approach may be acceptable for the repair of medial condylar fractures in 12-mm or thicker fragments. The compression achieved by a medial approach was not significantly greater for the 8, 12 or 20-mm groups. Clinical Relevance- Based on our results the 20 mm size fragments reaches a higher compression at a faster rate when compared to the 8 and 12 mm size fragments. We recommend using caution when repairing medial condylar fractures with a lateral approach for fragment sizes measuring 8-mm thick. The smaller fragment torque to failure was low and not much higher than the insertional torque. Failure resulted from the screws stripping in the bone fragment. The screws in the thicker fragments (12 and 20 mm) engage more bone and have a higher torque to failure as a result.
Subjects/Keywords: Condylar fracture
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APA (6th Edition):
Sprinkle, S. B. (2011). Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone. (Masters Thesis). Louisiana State University. Retrieved from etd-07072011-192636 ; https://digitalcommons.lsu.edu/gradschool_theses/729
Chicago Manual of Style (16th Edition):
Sprinkle, Saybl Beauton. “Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone.” 2011. Masters Thesis, Louisiana State University. Accessed February 17, 2020.
etd-07072011-192636 ; https://digitalcommons.lsu.edu/gradschool_theses/729.
MLA Handbook (7th Edition):
Sprinkle, Saybl Beauton. “Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone.” 2011. Web. 17 Feb 2020.
Vancouver:
Sprinkle SB. Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone. [Internet] [Masters thesis]. Louisiana State University; 2011. [cited 2020 Feb 17].
Available from: etd-07072011-192636 ; https://digitalcommons.lsu.edu/gradschool_theses/729.
Council of Science Editors:
Sprinkle SB. Biomechanical evaluation of medial and lateral approaches for experimentally created medial condylar fractures of the equine third metacarpal bone. [Masters Thesis]. Louisiana State University; 2011. Available from: etd-07072011-192636 ; https://digitalcommons.lsu.edu/gradschool_theses/729
University of Otago
12.
Adsett, Luke.
Patterns and trends in facial fractures in New Zealand
.
Degree: 2011, University of Otago
URL: http://hdl.handle.net/10523/2024
► Intro: Fracture of the human facial skeleton is a common injury that places serious burden on society. Severe morbidity, mortality, facial disfigurement, loss of function…
(more)
▼ Intro:
Fracture of the human facial skeleton is a common injury that places serious burden on society. Severe morbidity, mortality, facial disfigurement, loss of function and financial cost are all associated with facial fractures (Kieser et al., 2002). In New Zealand (NZ), only two previous studies have looked at the aetiology, incidence, age, gender and ethnic distribution of facial fractures at a national level; the most recent was conducted in 1998. In addition, approximately 40% of facial fractures in NZ involve the consumption of alcohol (Adams et al., 2000; Buchanan et al., 2005; Lee and Antoun, 2009; Tong et al., 2010). The legal purchasing age of alcohol in NZ, was lowered from 20 years of age to 18 years of age in December 1999. To date, no research has investigated what influence lowering the legal purchasing age of alcohol has had on the trends and patterns of facial fractures.
Aims: To describe the aetiology, incidence, age, gender and ethnic distribution of facial fractures in NZ from 1999 to 2009. To review the patterns and trends of facial fractures occurring in NZ from 1999 to 2009 with those previously identified. To identify whether lowering the legal alcohol purchasing age has influenced facial fractures. To identity whether Māori still experience a disproportionate risk of facial fractures with respect to other NZ ethnic groups.
Materials and Methods: This was a retrospective study investigating data on facial fractures that occurred between 30th June 1999 and 1st July 2009. Data were gathered from the Ministry of Health (MOH) and the Accident Compensation Corporation of New Zealand (ACC). Patient demographic characteristics and the details of injury (including alcohol involvement) were analysed and described.
Results: Over the study period, the incidence of facial fractures was constant and a total of 26,637 were coded by the MOH. Most facial fractures (78%) occurred in males, giving a male-to-female ratio of 4:1. Comparison of data for the period 1979 to 1998 highlighted that peak injury rates, especially in males, coincide with the legal alcohol purchasing age at the time. Since 1998, more injuries have occurred in the younger NZ population, with peak injury rates shifting from 20 years to 18 years of age. Interpersonal violence (IPV) is the leading cause of facial fractures in NZ accounting for almost 40% of all fractures. In addition, the number of injuries attributed to IPV is increasing each year. Māori still continue to experience a disproportionate level of facial fractures, twice that of the NZ European population.
Conclusion: IPV is an increasing problem in NZ and contributes to a greater number of facial fractures each year. More measures are required to reduce the number of IPV-related injuries. Perhaps the most influential would be to return the legal alcohol purchasing age to 20 years. More is also required to reduce facial fractures in the high-risk groups of young adults, males, and Māori.
Advisors/Committee Members: Thomson, William Murray (advisor).
Subjects/Keywords: Fracture;
Facial
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Export
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Manager
APA (6th Edition):
Adsett, L. (2011). Patterns and trends in facial fractures in New Zealand
. (Doctoral Dissertation). University of Otago. Retrieved from http://hdl.handle.net/10523/2024
Chicago Manual of Style (16th Edition):
Adsett, Luke. “Patterns and trends in facial fractures in New Zealand
.” 2011. Doctoral Dissertation, University of Otago. Accessed February 17, 2020.
http://hdl.handle.net/10523/2024.
MLA Handbook (7th Edition):
Adsett, Luke. “Patterns and trends in facial fractures in New Zealand
.” 2011. Web. 17 Feb 2020.
Vancouver:
Adsett L. Patterns and trends in facial fractures in New Zealand
. [Internet] [Doctoral dissertation]. University of Otago; 2011. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/10523/2024.
Council of Science Editors:
Adsett L. Patterns and trends in facial fractures in New Zealand
. [Doctoral Dissertation]. University of Otago; 2011. Available from: http://hdl.handle.net/10523/2024
Oregon State University
13.
Addison, Dylan, A.
Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air.
Degree: MS, 2017, Oregon State University
URL: http://hdl.handle.net/1957/61609
► Time-dependent crack growth mechanisms in Alloy 617 at 800°C in air were studied using compact tension samples machined in the L-T direction, cracked at temperature…
(more)
▼ Time-dependent crack growth mechanisms in Alloy 617 at 800°C in air were studied using compact tension samples machined in the L-T direction, cracked at temperature using an induction furnace and servo-hydraulic load frame. The application of different loading waveforms, including triangular, hold time, and sustained loading, were studied with relation to relevant crack tip parameters in order to better understand the material’s viscoplastic response to crack growth mechanisms.
Fracture surfaces and crack tip profiles were examined to discover relevant relationships between transgranular cracking, void growth and coalescence, and the role of oxygen embrittlement. A transition from transgranular cracking to void coalescence was noted, and the mechanism mapped, both onto the results obtained in this work and the existing literature. Additionally, overload experiments aided in describing stress relaxation as the dominant transgranular mechanism governing crack growth below Kth, the sustained load crack growth threshold stress intensity factor, which is also reported herein.
Advisors/Committee Members: Kruzic, Jamie, J. (advisor), Bay, Brian, K. (committee member).
Subjects/Keywords: Fracture Mechanics
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APA (6th Edition):
Addison, Dylan, A. (2017). Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/61609
Chicago Manual of Style (16th Edition):
Addison, Dylan, A. “Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air.” 2017. Masters Thesis, Oregon State University. Accessed February 17, 2020.
http://hdl.handle.net/1957/61609.
MLA Handbook (7th Edition):
Addison, Dylan, A. “Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air.” 2017. Web. 17 Feb 2020.
Vancouver:
Addison, Dylan A. Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air. [Internet] [Masters thesis]. Oregon State University; 2017. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1957/61609.
Council of Science Editors:
Addison, Dylan A. Time-Dependent Crack Growth Mechanisms in Alloy 617 at 800°C in Air. [Masters Thesis]. Oregon State University; 2017. Available from: http://hdl.handle.net/1957/61609
14.
Shekhawat, Ashivni.
Fracture In Brittle Disordered Media
.
Degree: 2013, Cornell University
URL: http://hdl.handle.net/1813/34107
► This thesis consists of three main chapters, an introduction, and an appendix. The introduction (chapter 1) gives a general historical introduction to the problem of…
(more)
▼ This thesis consists of three main chapters, an introduction, and an appendix. The introduction (chapter 1) gives a general historical introduction to the problem of brittle
fracture in disordered media. Chapters 2 and 4 are concerned with various aspects of
fracture in disordered fuse networks. Chapter 2 investigates the asymptotic properties of
fracture strength distributions, and explores their relation with extreme value statistics. Chapter 4 deals with critical phenomena in brittle
fracture. This chapter introduces the concept of finite-sized criticality as a means to explain how
fracture can have mixed properties of abrupt and continuous phase transitions. Chapter 3 describes the collective dynamics at the non equilibrium metal insulator transition. The phenomenon of dielectric breakdown at the metal insulator transition shares several characteristics with
fracture, and provides a suitable build up to the development presented in chapter 4. The first three parts of the appendix provide an introduction to the various mathematical tools required in order to better appreciate the content of this thesis. Appendix A.1 discusses the basics of extreme value theory, while A.2 and A.3 provide a light introduction to linear elastic
fracture mechanics. Appendix A.4 summaries some results on crack propagation in graphene that are not sufficiently well developed to merit a chapter, and yet are developed enough to merit a mention.
Advisors/Committee Members: Resnick, Sidney Ira (committeeMember), Phoenix, Stuart Leigh (committeeMember).
Subjects/Keywords: Fracture
…A Appendix
A.1 Extreme Value Statistics . . . . . . .
A.2 Linear Elastic Fracture… …insulator transition . . . . . . . . . .
36
38
40
4.1
4.2
4.3
Fracture in the fuse network at… …varying disorder . . . . . . . . . .
A scaling theory of fracture… …Phase diagram for brittle fracture in disordered media . . . . . .
45
50
53
Polar… …74
75
76
CHAPTER 1
INTRODUCTION
This is a thesis about fracture or how and why things…
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APA (6th Edition):
Shekhawat, A. (2013). Fracture In Brittle Disordered Media
. (Thesis). Cornell University. Retrieved from http://hdl.handle.net/1813/34107
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Shekhawat, Ashivni. “Fracture In Brittle Disordered Media
.” 2013. Thesis, Cornell University. Accessed February 17, 2020.
http://hdl.handle.net/1813/34107.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Shekhawat, Ashivni. “Fracture In Brittle Disordered Media
.” 2013. Web. 17 Feb 2020.
Vancouver:
Shekhawat A. Fracture In Brittle Disordered Media
. [Internet] [Thesis]. Cornell University; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1813/34107.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Shekhawat A. Fracture In Brittle Disordered Media
. [Thesis]. Cornell University; 2013. Available from: http://hdl.handle.net/1813/34107
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Texas – Austin
15.
Dana, Saumik P.
Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid.
Degree: MSin Engineering, Engineering Mechanics, 2014, University of Texas – Austin
URL: http://hdl.handle.net/2152/28538
► In this report, we develop a computational procedure to investigate propagation of 3D cracks in isotropic linearly elastic media in a 2D framework. We reduce…
(more)
▼ In this report, we develop a computational procedure to investigate propagation of 3D cracks in isotropic linearly elastic media in a 2D framework. We reduce the 3D weakly singular, weak-form traction integral equation to its 2D analog by introducing a constraint on crack profile in out-of-plane direction. Symmetric Galerkin boundary element method based on the obtained 2D weak-form traction integral equation is adopted to model these fractures. In particular, we consider multiple interacting cracks in unbounded domain
subject to internal pressure to model hydraulic
fracture.
Advisors/Committee Members: Mear, Mark E. (advisor).
Subjects/Keywords: Hydraulic fracture
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APA (6th Edition):
Dana, S. P. (2014). Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/28538
Chicago Manual of Style (16th Edition):
Dana, Saumik P. “Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid.” 2014. Masters Thesis, University of Texas – Austin. Accessed February 17, 2020.
http://hdl.handle.net/2152/28538.
MLA Handbook (7th Edition):
Dana, Saumik P. “Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid.” 2014. Web. 17 Feb 2020.
Vancouver:
Dana SP. Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid. [Internet] [Masters thesis]. University of Texas – Austin; 2014. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/2152/28538.
Council of Science Editors:
Dana SP. Simulation of growth of multiple interacting 3D cracks in hydraulic fractures driven by inviscid fluid. [Masters Thesis]. University of Texas – Austin; 2014. Available from: http://hdl.handle.net/2152/28538
Dalhousie University
16.
Allan, Andrew.
A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures.
Degree: Master of Applied Science, Department of Biomedical Engineering, 2012, Dalhousie University
URL: http://hdl.handle.net/10222/15396
► Distal radius fractures are the single most common type of fracture suffered among the adult population. Presently, clinical decision making regarding optimal treatment is inconclusive.…
(more)
▼ Distal radius fractures are the single most common
type of
fracture suffered among the adult population. Presently,
clinical decision making regarding optimal treatment is
inconclusive. The goal of this thesis was to design, develop, and
biomechanically test a novel implant for the stabilization of
distal radius fractures. The novel implant is intended to provide a
minimally invasive, low cost alternative to locked volar plates,
while still permitting an earlier return to function. The implant
consists of an angled bar with a sharp cutting edge and is inserted
using a minimally invasive approach through the radial styloid.
Surgical instrumentation was designed to facilitate the procedure
in a controlled manner. To determine whether the implant would be
capable of providing an early return to function, biomechanical
tests were conducted both experimentally and numerically.
Biomechanical testing showed that mechanical fixation with the
novel implant does not support and early return to
function.
Advisors/Committee Members: Dr. Darrel Doman (external-examiner), Dr. Sarah Wells (graduate-coordinator), Dr. Janie Astephen-Wilson (thesis-reader), Dr. Mark Filiaggi (thesis-reader), Dr. Michael Dunbar (thesis-supervisor), Not Applicable (ethics-approval), Not Applicable (manuscripts), Not Applicable (copyright-release).
Subjects/Keywords: Biomechanical, Distal Radius, Fracture Fixation; Fracture
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APA (6th Edition):
Allan, A. (2012). A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures. (Masters Thesis). Dalhousie University. Retrieved from http://hdl.handle.net/10222/15396
Chicago Manual of Style (16th Edition):
Allan, Andrew. “A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures.” 2012. Masters Thesis, Dalhousie University. Accessed February 17, 2020.
http://hdl.handle.net/10222/15396.
MLA Handbook (7th Edition):
Allan, Andrew. “A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures.” 2012. Web. 17 Feb 2020.
Vancouver:
Allan A. A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures. [Internet] [Masters thesis]. Dalhousie University; 2012. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/10222/15396.
Council of Science Editors:
Allan A. A Biomechanical Investigation of a Novel Implant for the
Stabilization of Distal Radius Fractures. [Masters Thesis]. Dalhousie University; 2012. Available from: http://hdl.handle.net/10222/15396
Texas A&M University
17.
Oeth, Cassandra V.
Three-dimensional Modeling of Acid Transport and Etching in a Fracture.
Degree: 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151892
► Acid fracture stimulation generates higher well production but requires engineering design for treatment optimization. To quantify the cost and benefit of a particular acid fracture…
(more)
▼ Acid
fracture stimulation generates higher well production but requires engineering design for treatment optimization. To quantify the cost and benefit of a particular acid
fracture treatment an engineer must predict the resulting
fracture?s conductivity, which is based on the etched width created by the injected acid. Etching occurs along the
fracture surface but is based on acid flowing through the
fracture, so an evaluation tool should describe three-dimensional physics and chemistry. Current practice is to estimate conductivity utilizing two-dimensional models. Unfortunately, these models necessarily assume how acid is distributed in the
fracture and often misrepresent the amount of acid etching upon which the conductivity is based.
A fully three-dimensional modeling tool to evaluate and predict acid
fracture performance across the wide range of carbonate field properties has been developed. The model simulates acid transport and
fracture face dissolution. The acid transport model includes the solution of the three-dimensional velocity and pressure fields, the non-Newtonian characteristics of most acid fracturing fluids, and diffusion of acid toward the
fracture surface. The model numerically solves the equations describing the three-dimensional acid transport and reaction within a
fracture to yield the etched width created by acid along the
fracture. The conductivity is calculated with the simulator derived acid-etched width, using correlations recently developed that reflect the small scale heterogeneity of carbonate rock as it creates etching along the
fracture surface.
The performance of an acid
fracture treatment is quantified with conductivity, which is strongly dependent on the etched width created by the acid. This robust new tool more accurately models the impact of design decisions on the acid-etched width and provides a rational path for treatment optimization. Cases typical of industry practice are presented that demonstrate the model capabilities.
Advisors/Committee Members: Hill, Alfred D (advisor), Zhu, Ding (committee member), Gildin, Eduardo (committee member), Handler, Robert A (committee member).
Subjects/Keywords: acid fracturing; fracture acidizing; fracture simulation
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APA (6th Edition):
Oeth, C. V. (2013). Three-dimensional Modeling of Acid Transport and Etching in a Fracture. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151892
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Oeth, Cassandra V. “Three-dimensional Modeling of Acid Transport and Etching in a Fracture.” 2013. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/151892.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Oeth, Cassandra V. “Three-dimensional Modeling of Acid Transport and Etching in a Fracture.” 2013. Web. 17 Feb 2020.
Vancouver:
Oeth CV. Three-dimensional Modeling of Acid Transport and Etching in a Fracture. [Internet] [Thesis]. Texas A&M University; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/151892.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Oeth CV. Three-dimensional Modeling of Acid Transport and Etching in a Fracture. [Thesis]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151892
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Clemson University
18.
Rogers, Margeaux.
Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia.
Degree: MS, Bioengineering, 2013, Clemson University
URL: https://tigerprints.clemson.edu/all_theses/1675
► Salter-Harris fractures of the proximal tibia and distal femur are common in pediatric patients that present to orthopedic surgeons. Salter-Harris type I fractures are…
(more)
▼ Salter-Harris fractures of the proximal tibia and distal femur are common in pediatric patients that present to orthopedic surgeons. Salter-Harris type I fractures are characterized by breaks that extend only through the physis while Salter-Harris II fractures are the most common, accounting for 85% of Salter-Harris fractures, and extend past the growth plate, exiting through the metaphyseal bone1. Fixation of these
fracture types can be accomplished using a variety of methods including the use of Kirschner wires, cannulated screws, and a combination of both materials. Stability of
fracture fixation is of utmost importance as persistent motion at the
fracture margin leads to deformity2. Other complications resulting from unsuccessful
fracture treatment include knee instability, premature physeal closure, and leg shortening causing the patient to experience a higher physiological load1,3. The purpose of this study is to analyze the biomechanical efficacy of common fixation methods used to stabilize Salter-Harris I and II
fracture patterns in both the proximal tibia and distal femur. Rotational stiffness will be used as the primary gauge of efficacy and is tested in flexion and extension, varus and valgus rotation, and internal and external rotation. Comparison of stiffness will be used to determine the optimal fixation method specific to each bone and
fracture pattern. This study utilized 39 tibia and 36 femur 4th generation synthetic bones, fractured and fixated to model Salter-Harris type I and II fractures and common fixation methods. Fixation methods used employed 6.5mm cannulated screws, 4.5mm cannulated screws, 2mm smooth k-wires, and 2mm threaded k-wires. Cyclic displacement tests were performed on a materials testing machine which recorded the torque required to reach an angulation of ±5¡ for 10 cycles. Statistical analysis was performed to compare construct stiffness and differences between groups using analysis of variance. Results show superior stability achieved through the use of threaded k-wires for both femoral and tibial Salter-Harris type I
fracture fixation. The optimal femoral Salter-Harris type II fixation method utilized two oblique screws. Methods consisting of a combination of screws and k-wires resulted in the greatest rotational stiffness for tibial Salter-Harris type II fractures. Improvements in fixation methods should be considered to enhance internal and external rotational stiffness for all
fracture types.
Advisors/Committee Members: DesJardins, John D, LaBerge , Martine, Nagatomi , Jiro.
Subjects/Keywords: biomechanics; fracture fixation; physeal fracture; Biomechanics
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APA (6th Edition):
Rogers, M. (2013). Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1675
Chicago Manual of Style (16th Edition):
Rogers, Margeaux. “Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia.” 2013. Masters Thesis, Clemson University. Accessed February 17, 2020.
https://tigerprints.clemson.edu/all_theses/1675.
MLA Handbook (7th Edition):
Rogers, Margeaux. “Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia.” 2013. Web. 17 Feb 2020.
Vancouver:
Rogers M. Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia. [Internet] [Masters thesis]. Clemson University; 2013. [cited 2020 Feb 17].
Available from: https://tigerprints.clemson.edu/all_theses/1675.
Council of Science Editors:
Rogers M. Biomechanical Testing of Salter-Harris Fractures Type I and II in the Distal Femur and Proximal Tibia. [Masters Thesis]. Clemson University; 2013. Available from: https://tigerprints.clemson.edu/all_theses/1675
University of Texas – Austin
19.
Doungkaew, Natchanan.
Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California.
Degree: MSin Geological Sciences, Geological Sciences, 2016, University of Texas – Austin
URL: http://hdl.handle.net/2152/47091
► Processes of fracture formation control flow of fluid in the subsurface and the mechanical properties of the brittle crust. I investigate whether fracture aperture profiles…
(more)
▼ Processes of
fracture formation control flow of fluid in the subsurface and the mechanical properties of the brittle crust. I investigate whether
fracture aperture profiles describing the opening displacement along their height or length reflect
fracture growth conditions and mechanisms. I hypothesize that aperture profiles of fractures growing under different environments and by different mechanisms have different ellipticity. I measured
fracture profiles for quartz cemented opening-mode fractures in low-grade metamorphic sandstone of the Campito Formation, eastern California, and quantified their ellipticity using curve fitting methods based on the Lamé function. I compare the Lamé parameter n against structural and inferred environmental parameters, including
fracture orientation,
fracture tip characteristics, locations of
fracture tips relative to layer boundaries, texture of
fracture cements, and temperature during
fracture growth as determined through fluid inclusion homogenization temperatures. Lamé n values range from 0.72 to 3.20, with the majority falling between 1 and 1.5.
Fracture with n < 2 correlate with higher fluid inclusion homogenization temperatures between 270°C and 315°C, and are preferentially filled with blocky quartz cement. Fractures with fluid inclusion temperatures in the range of 150°C and 250°C have n~ 2 and preferentially contain crack-seal quartz cement. I observe no correlation between n and
fracture orientation, and aperture/length ratio, although fractures with wide apertures have n<2.
To explain fractures with n<2 we propose a
fracture growth mechanism consisting of elastic opening increments followed by stages of stress dissipation in the
fracture tip regions. Kinematic models suggest that rapid length or height growth with slow aperture growth results in
fracture aperture profiles with n~1.
Fracture aperture profiles with n>2 require opening increments with blunt tips and slow length or height growth relative to aperture growth. Our model is consistent with faster length growth resulting from reduced
fracture toughness with increasing temperature, leading to low n at higher temperatures. The absence of crack-seal cement in fractures with low n may relate to overall fast
fracture growth at higher temperatures, with aperture growth exceeding rates of synkinematic crack-seal quartz cementation. Fractures with n>2 require tip blunting that I attribute to enhanced solution-precipitation creep by stress concentration at the
fracture tip.
Advisors/Committee Members: Eichhubl, Peter (advisor), Behr, Whitney (committee member), Fisher, William (committee member).
Subjects/Keywords: Fracture aperture profiles; Kinematic fracture growth models
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APA (6th Edition):
Doungkaew, N. (2016). Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/47091
Chicago Manual of Style (16th Edition):
Doungkaew, Natchanan. “Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California.” 2016. Masters Thesis, University of Texas – Austin. Accessed February 17, 2020.
http://hdl.handle.net/2152/47091.
MLA Handbook (7th Edition):
Doungkaew, Natchanan. “Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California.” 2016. Web. 17 Feb 2020.
Vancouver:
Doungkaew N. Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California. [Internet] [Masters thesis]. University of Texas – Austin; 2016. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/2152/47091.
Council of Science Editors:
Doungkaew N. Fracture aperture profiles as indicators of fracture growth environments : an integrated study of fracture aperture growth in the Campito Formation of eastern California. [Masters Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/47091
Hong Kong University of Science and Technology
20.
Xie, Tao.
Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading.
Degree: 2013, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-62370
;
https://doi.org/10.14711/thesis-b1255097
;
http://repository.ust.hk/ir/bitstream/1783.1-62370/1/th_redirect.html
► The effect of electrostatic tractions on the fracture behavior of a dielectric material under mechanical and/or electric loading is analyzed first by studying a pre-cracked…
(more)
▼ The effect of electrostatic tractions on the fracture behavior of a dielectric material under mechanical and/or electric loading is analyzed first by studying a pre-cracked parallel-plate capacitor and illustrated by plots. The research is then extended into the case of piezoelectric materials considering the anisotropic material properties and the piezoelectric effect. The results are illustrated by plots based on a specific lead zirconate titanate (PZT-5H) sample, and also for another piezoelectric material with even higher dielectric/piezoelectric constants. The results are presented in terms of electrostatic tractions, crack opening/closing, and energy release rate. For dielectric materials, electrostatic tractions on the electrodes compress the material in front of the crack tip and stretch the material behind the crack tip, having the tendency to close the crack. Mechanical load is the driving force to propagate the crack, while applied electric field retards crack propagation due to the electrostatic tractions. As a direct consequence, the fracture criterion is composed of two parts: the energy release rate must exceed a critical value and the mechanical load must be higher than the critical value for crack opening. The investigation into piezoelectric materials indicates that influence of electrostatic tractions depends on the direction of applied electric field due to the piezoelectric effect. Under a positive electric field (aligned with the poling direction), the electrostatic tractions stretch the material behind the crack tip and have the tendency to close the crack. While under a negative electric field (opposite to the poling direction), the electrostatic tractions compress the material behind the crack tip and promotes crack opening process. Mechanical load is always the driving force to propagate the crack, while the effect of electric loading on the crack propagation due to the electrostatic tractions depends on applied electric field direction. The fracture criterion is composed of two parts: the energy release rate must exceed a critical value and the mechanical load must be higher than the critical value for crack opening. Special attention has to be paid to the loading condition under negative electric field due to its contribution to assisting in the crack opening process.
Subjects/Keywords: Piezoelectric materials
; Fracture
; Dielectrics
; Fracture mechanics
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APA ·
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CSE |
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APA (6th Edition):
Xie, T. (2013). Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-62370 ; https://doi.org/10.14711/thesis-b1255097 ; http://repository.ust.hk/ir/bitstream/1783.1-62370/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Xie, Tao. “Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading.” 2013. Thesis, Hong Kong University of Science and Technology. Accessed February 17, 2020.
http://repository.ust.hk/ir/Record/1783.1-62370 ; https://doi.org/10.14711/thesis-b1255097 ; http://repository.ust.hk/ir/bitstream/1783.1-62370/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Xie, Tao. “Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading.” 2013. Web. 17 Feb 2020.
Vancouver:
Xie T. Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2013. [cited 2020 Feb 17].
Available from: http://repository.ust.hk/ir/Record/1783.1-62370 ; https://doi.org/10.14711/thesis-b1255097 ; http://repository.ust.hk/ir/bitstream/1783.1-62370/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Xie T. Effect of electrostatic tractions on the fracture behavior of a dielectric/piezoelectric material under mechanical and/or electric loading. [Thesis]. Hong Kong University of Science and Technology; 2013. Available from: http://repository.ust.hk/ir/Record/1783.1-62370 ; https://doi.org/10.14711/thesis-b1255097 ; http://repository.ust.hk/ir/bitstream/1783.1-62370/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Hong Kong University of Science and Technology
21.
Chen, E.
Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics.
Degree: 2011, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-7386
;
https://doi.org/10.14711/thesis-b1154860
;
http://repository.ust.hk/ir/bitstream/1783.1-7386/1/th_redirect.html
► Biaxial compression tests on cubic concrete specimens were performed on a newly designed triaxial machine. Specially designed steel brush platens were adopted in biaxial experiments…
(more)
▼ Biaxial compression tests on cubic concrete specimens were performed on a newly designed triaxial machine. Specially designed steel brush platens were adopted in biaxial experiments to reduce the end friction in order to obtain real uniform compression state in the specimens. Concrete with different maximum aggregate sizes were tested for their biaxial compressive strength, with fracture energy and characteristic length examined at the same time. It was found that the biaxial compressive strength of concrete was intrinsically dependent on the fracture energy and characteristic length rather than the uniaxial strength. Therefore, by introducing the fracture parameters, a trend of biaxial failure envelope can be more accurately described than previous research in which the uniaxial strength was always taken as the basis for deriving the envelope. This finding may provide a more accurate design criterion based on fracture parameters in multiaxial problems. On the other hand, numerical simulation of concrete behavior under uniaxial tension, uniaxial compression and combined compression-tension was carried out based on a proposed local softening model by the nonlinear finite element software ATENA. Pure mode I crack was assumed under uniaxial tension and the equivalent wing crack system was employed for uniaxial compression and biaxial compression-tension. The local softening behavior was simulated by means of the interface material model in ATENA. The relationships among the uniaxial compressive strength, tensile strength and the fracture energy under tension were well reproduced compared with the empirical relations. This implies that the local softening law can be viewed as the linkage of these macroscopic properties. Numerical biaxial compressive-tensile strengths based on the local softening model also showed good agreement with available experimental results. Therefore, non-linear fracture mechanics with the local softening law at the sub-macro-scale seems to be suitable for analyzing concrete behaviors at the macro-scale.
Subjects/Keywords: Concrete – Fracture – Mathematical models
; Fracture mechanics
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APA (6th Edition):
Chen, E. (2011). Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-7386 ; https://doi.org/10.14711/thesis-b1154860 ; http://repository.ust.hk/ir/bitstream/1783.1-7386/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chen, E. “Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics.” 2011. Thesis, Hong Kong University of Science and Technology. Accessed February 17, 2020.
http://repository.ust.hk/ir/Record/1783.1-7386 ; https://doi.org/10.14711/thesis-b1154860 ; http://repository.ust.hk/ir/bitstream/1783.1-7386/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chen, E. “Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics.” 2011. Web. 17 Feb 2020.
Vancouver:
Chen E. Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2011. [cited 2020 Feb 17].
Available from: http://repository.ust.hk/ir/Record/1783.1-7386 ; https://doi.org/10.14711/thesis-b1154860 ; http://repository.ust.hk/ir/bitstream/1783.1-7386/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chen E. Study on concrete strength under uniaxial and biaxial loadings from the view of fracture mechanics. [Thesis]. Hong Kong University of Science and Technology; 2011. Available from: http://repository.ust.hk/ir/Record/1783.1-7386 ; https://doi.org/10.14711/thesis-b1154860 ; http://repository.ust.hk/ir/bitstream/1783.1-7386/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
22.
Lesaine, Arnaud.
Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales.
Degree: Docteur es, Mécanique des matériaux, 2018, Université Paris-Saclay (ComUE)
URL: http://www.theses.fr/2018SACLS597
► Le séchage d’une suspension colloïdale produit une couche solide plus ou moins poreuse. Ce processus intervient dans de nombreuses applications, telles que le procédé sol-gel…
(more)
▼ Le séchage d’une suspension colloïdale produit une couche solide plus ou moins poreuse. Ce processus intervient dans de nombreuses applications, telles que le procédé sol-gel ou la fabrication de laques et de peintures. Durant le séchage, l’évaporation du solvant entraîne la rétraction du matériau ; des contraintes importantes peuvent alors apparaître dans les couches colloïdales, les rendant susceptibles de se fracturer. Il est ainsi crucial de comprendre l’influence de paramètres de contrôle tels que la vitesse de séchage, l’épaisseur de la couche ou la taille de particule sur les propriétés mécaniques et de structure du matériau final. Dans cette thèse, nous avons utilisé des suspensions de Ludox (silice colloïdale) comme système modèle afin d’étudier l’effet de la vitesse de séchage sur les propriétés du matériau solide obtenu. Dans une première partie, nous avons mis en œuvre des mesures de porosité, ainsi que de microscopie à force atomique et de diffraction de rayons X, afin de caractériser l’effet de la vitesse de séchage sur les propriétés de structure des couches sèches. Nous avons mis en évidence l’importance de la polydispersité des suspensions initiales, ainsi que des phénomènes d’agrégation de particules, sur la structure et la compacité du matériau obtenu. Dans une deuxième partie, des mesures de constantes élastiques par propagation d’ultrasons nous ont permis de déterminer l’élasticité tensorielle (i.e. le module de compressibilité et celui de cisaillement) des couches colloïdales. Ces modules élastiques dépendent de la porosité du matériau ainsi que de la taille des particules de silice. Les données expérimentales ont été comparées aux prédictions de deux schémas d’homogénéisation (Mori-Tanaka et auto-cohérent), ainsi qu’au modèle de Kendall pour le module d’Young, qui prend en considération une énergie d’adhésion entre les particules. Enfin, nous avons déterminé la résistance à la fracture des couches colloïdales à l’aide de tests d’indentation Vickers. Cette résistance à la fracture, mesurée à la fin du séchage, est mise en relation avec la vitesse d’évaporation, la porosité du matériau, ainsi que la densité de fractures observées pendant le processus d’évaporation du solvant.
Drying a colloidal suspension results in the formation of a more or less porous solid layer. This procedure is central to many applications such as sol-gel processes, the design of paints and lacquers... As the solvent evaporation induces shrinkage of the material, large stresses can develop in these layers, making them prone to fracture. A crucial challenge is thus to understand the role of the control parameters, such as drying rate, film thickness and particle size, on the structural and mechanical properties of the final layer. In this thesis work, Ludox (colloidal silica) was used as a model system to study the effect of the drying rate on the structural and mechanical properties of the resultant solid. The effect of the drying rate on the structural properties of the dry layers was studied using porosity…
Advisors/Committee Members: Lazarus, Véronique (thesis director), Rountree, Cindy (thesis director).
Subjects/Keywords: Colloïdes; Séchage; Fracture; Colloids; Drying; Fracture
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APA ·
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Manager
APA (6th Edition):
Lesaine, A. (2018). Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2018SACLS597
Chicago Manual of Style (16th Edition):
Lesaine, Arnaud. “Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales.” 2018. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed February 17, 2020.
http://www.theses.fr/2018SACLS597.
MLA Handbook (7th Edition):
Lesaine, Arnaud. “Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales.” 2018. Web. 17 Feb 2020.
Vancouver:
Lesaine A. Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2018. [cited 2020 Feb 17].
Available from: http://www.theses.fr/2018SACLS597.
Council of Science Editors:
Lesaine A. Structural and mechanical properties of dried colloidal silica layers : Propriétés mécaniques et de structure de films formés par évaporation de suspensions colloïdales. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2018. Available from: http://www.theses.fr/2018SACLS597
Texas A&M University
23.
Kumar, Amrendra.
Effective fracture geometry obtained with large water sand ratio.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2359
► Shale gas formation exhibits some unusual reservoir characteristics: nano-darcy matrix permeability, presence of natural fractures and gas storage on the matrix surface that makes it…
(more)
▼ Shale gas formation exhibits some unusual reservoir characteristics: nano-darcy
matrix permeability, presence of natural fractures and gas storage on the matrix
surface that makes it unique in many ways. It?s difficult to design an optimum
fracture treatment for such formation and even more difficult is to describe
production behavior using a reservoir model. So far homogeneous, two wing
fracture, and natural
fracture models have been used for this purpose without much
success. Micro seismic mapping technique is used to measure the
fracture
propagation in real time. This measurement in naturally fractured shale formation
suggests a growth of
fracture network instead of a traditional two wing fractures.
There is an industry wise consensus that
fracture network plays an important role in
determining the well productivity of such formations. A well with high density of
fracture networks supposed to have better productivity.
Shale formations have also exhibited production pattern which is very
different from conventional or tight gas reservoir. Initial flow period is marked by
steep decline in production while the late time production exhibits a slow decline.
One of the arguments put for this behavior is linear flow from a bi-wing fractured
well at early time and contribution of adsorbed gas in production at late time. However, bi-wing
fracture geometry is not supported by the micro-seismic
observation. A realistic model should include both the
fracture network and adsorbed
gas property.
In this research we have proposed a new Power Law Permability model to
simulate fluid flow from hydraulically fractured Shale formation. This model was
first described by Valko & Fnu (2002) and used for analyzing acid treatment jobs.
The key idea of this model is to use a power law permeability function that varies
with the radial distance from well bore. Scaling exponent of this power law function
has been named power law index. The permeability function has also been termed as
secondary permeability.
This work introduces the method of Laplace solution to solve the problem of
transient and pseudo steady-state flow in a
fracture network. Development and
validation of this method and its extension to predict the pressure (and production)
behaviour of
fracture network were made using a novel technic. Pressure solution
was then combined with material balance through productivity index to make
production forecast.
Reservoir rock volume affected by the
fracture stimulation treatment that
contributes in the production is called effective stimulated volume. This represents
the extent of
fracture network in this case. Barnett shale formation is a naturally
fractured shale reservoir in Fort Worth basin. Several production wells from this
formation was analysed using Power Law Model and it was found that wells
productivity are highly dependent on stimulated volume. Apparently the wells flow
under pseudo steady state for most part of their producing life and the effect of
boundary on production is evident in as soon as one months of production. Due…
Advisors/Committee Members: Valko, Peter,P (advisor), Economides,Ehlig (committee member), Guermond, Jean-Luc (committee member).
Subjects/Keywords: Fracture; Shale Gas
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APA (6th Edition):
Kumar, A. (2009). Effective fracture geometry obtained with large water sand ratio. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2359
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kumar, Amrendra. “Effective fracture geometry obtained with large water sand ratio.” 2009. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/ETD-TAMU-2359.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kumar, Amrendra. “Effective fracture geometry obtained with large water sand ratio.” 2009. Web. 17 Feb 2020.
Vancouver:
Kumar A. Effective fracture geometry obtained with large water sand ratio. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2359.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kumar A. Effective fracture geometry obtained with large water sand ratio. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2359
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
24.
Underwood, Jarrod.
Acid Fracture and Fracture Conductivity Study of Field Rock Samples.
Degree: 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151691
► Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of…
(more)
▼ Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of acid interaction on specific rock samples can be studied experimentally. Acid injection data and
fracture conductivity measurements obtained in the research presented in this thesis yielded results that qualified and quantified the impact of a specific acid system on rock samples of varying acid solubility.
Six rock samples from a carbonate reservoir were labeled A through F to protect proprietary information included in this research. A 2% potassium chloride solution was used for the acid system and
fracture conductivity measurements to prevent clay swelling. Injection temperature, contact time, and injection rate were designed to simulate field treatment conditions. The effects of a chelating agent on
fracture conductivity were also studied.
Before and after images of the rock samples indicated that the effect of 15% hydrochloric acid on the samples was limited but correlated with the rock acid solubility. Samples E and F had a greater value of acid solubility and showed noticeable surface etching. Samples A, B, and C had lower values of acid solubility and did not show signs of surface etching. Sample D was of moderate acid solubility and showed minimal signs of surface etching.
Fracture conductivity did not correlate directly with acid solubility, but likely was a function of inherent matrix permeability based on leak-off measurements and
fracture conductivity measurements. Finally, the
fracture conductivity of Sample D increased after exposure to a chelating agent.
Commonly, acid
fracture experimental studies are carried out with outcrop rock samples. The samples have more homogenous properties and without hydrocarbon content. In this study, cores from downhole formation were used. The original condition was preserved as much as possible to simulate real field situations. However, using field rock samples does present challenges not generally associated with outcrop rock samples.
Based on the information gathered from the work presented in this thesis, conclusions were drawn concerning the effectiveness of a 15% hydrochloric acid treatment in this formation and the challenges of using field rock samples.
Advisors/Committee Members: Zhu, Ding (advisor), Hill, A D (committee member), Ugaz, Victor (committee member).
Subjects/Keywords: Acid Fracture; carbonate
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Underwood, J. (2013). Acid Fracture and Fracture Conductivity Study of Field Rock Samples. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151691
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Underwood, Jarrod. “Acid Fracture and Fracture Conductivity Study of Field Rock Samples.” 2013. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/151691.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Underwood, Jarrod. “Acid Fracture and Fracture Conductivity Study of Field Rock Samples.” 2013. Web. 17 Feb 2020.
Vancouver:
Underwood J. Acid Fracture and Fracture Conductivity Study of Field Rock Samples. [Internet] [Thesis]. Texas A&M University; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/151691.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Underwood J. Acid Fracture and Fracture Conductivity Study of Field Rock Samples. [Thesis]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151691
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
25.
Marongiu-Porcu, Matteo.
A Global Model for Fracture Falloff Analysis.
Degree: 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/153914
► The reservoir permeability is an essential input for the optimum design of modern hydraulic fracture treatments, which are undeniably the crucial technology involved in the…
(more)
▼ The reservoir permeability is an essential input for the optimum design of modern hydraulic
fracture treatments, which are undeniably the crucial technology involved in the development of tight and/or unconventional gas reservoirs. The
fracture geometry and pumping execution, as well as the well architecture, can be designed to maximize the well productivity, provided the reservoir permeability is known, but in tight formations estimation of permeability and pressure can be impractical or even impossible to determine by conventional pressure buildup transient tests because no flow will occur without hydraulic
fracture stimulation.
Various authors have shown how
fracture calibration tests, intended for the final
fracture treatment calibration (i.e. estimation of closure stress, leakoff coefficient and
fracture fluid efficiency) can be used to estimate reservoir permeability as well. However, all the proposed techniques depend on specialized plots that are designed to show a straight line for a portion of the data, from which parameters are determined either from the slope of the line or from its endpoints, and there is a risk that apparent straight lines may lead to erroneous results, particularly when the absence of late time pseudo-radial flow data is ignored or not recognized.
This dissertation introduces a new global model for the before-closure and after-closure analysis of the pressure falloff following a step-rate or constant rate
fracture calibration test, using a single log-log diagnostic plot, as common practice within the pressure transient analysis literature. This model provides a complete assessment tool that allows quantification of all
fracture parameters (closure stress, closure time,
fracture fluid efficiency, leakoff coefficient and estimate of the induced
fracture geometry) as well as reservoir permeability and formation pressure, provided that enough time is allowed for the falloff to reach pseudo-radial flow regime. Both oil and gas reservoirs can be effectively studied.
Another major advantage provided by this approach is that this model can be used to optimize a priori the design of the
fracture calibration test that would allow determination of all the involved parameters, including reservoir permeability.
Field data will be used to validate the model and demonstrate its added value over current interpretation methods.
Advisors/Committee Members: Ehlig-Economides, Christine A (advisor), Nasr-El-Din, Hisham (committee member), Valko, Peter (committee member), Sun, Yuefeng (committee member).
Subjects/Keywords: falloff; fracture; model
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APA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Marongiu-Porcu, M. (2014). A Global Model for Fracture Falloff Analysis. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153914
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Marongiu-Porcu, Matteo. “A Global Model for Fracture Falloff Analysis.” 2014. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/153914.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Marongiu-Porcu, Matteo. “A Global Model for Fracture Falloff Analysis.” 2014. Web. 17 Feb 2020.
Vancouver:
Marongiu-Porcu M. A Global Model for Fracture Falloff Analysis. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/153914.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Marongiu-Porcu M. A Global Model for Fracture Falloff Analysis. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153914
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
26.
Kondori, Babak.
Ductile Fracture of Magnesium Alloys: Characterization and Modeling.
Degree: 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155053
► Magnesium alloys are prime potential candidates for lightweight structural applications because of their superior specific stiffness and strength. However, their effective insertion in transportation vehicles…
(more)
▼ Magnesium alloys are prime potential candidates for lightweight structural applications because of their superior specific stiffness and strength. However, their effective insertion in transportation vehicles hinges on improving their ductility and developing cost-effective forming technologies. Here, the processes of damage initiation and accumulation to
fracture are investigated at ambient temperature, experimentally and theoretically, in two Mg alloys, AZ31 and WE43. Material AZ31 exhibits strong basal texture whereas WE43 has a weak non-basal texture with quasiisotropic properties. The microstructural characterization is carried out on the initial materials aiming at determining the texture, the grain size/shape distribution as well as the chemical composition, volume fraction, shape and spatial arrangement of second-phase particles. The macroscopic plastic flow anisotropy is characterized using round tensile bars and compression pins along three principal and three off-axes orientations. Semi-continuous measurement of diameter contraction in two orthogonal directions enabled the monitoring of relative volume change and strain-ratio evolution. The data is used to model the plastic anisotropy of the materials using models from the literature. A significant increase in volume is measured during plastic deformation. Macroscopic
fracture loci, along two principal and one off-axis directions, are obtained for each material using round notched bars of varying notch acuity so as to study the effect of stress triaxiality and directionality on flow and
fracture. It was found that notched AZ31 bars exhibit higher failure strain than uniaxial specimens. Second phase particles and deformation twins are identified as critical sites for damage initiation. Experiments also indicate that WE43 and AZ31 display significantly different sensitivities to stress triaxiality. Substantial drop in the failure strains of WE43 with increasing triaxiality is attributed to intergranular
fracture. Image analysis is performed on specimens deformed to incipient and complete
fracture to infer the distribution properties of voids and particles. A micromechanics-based continuum damage model is used to rationalize the main experimental trends and explore conflicting hypotheses. The model has two components: (i) a shape-dependent void growth; and (ii) a shape-dependent void/crack coalescence part. The results provide the groundwork for understanding the effects of microstructural and loading variables on damage and
fracture in magnesium alloys.
Advisors/Committee Members: Benzerga, Amine A (advisor), Karaman, Ibrahim (committee member), Arr?yave, Raymundo (committee member), Lagoudas, Dimitris C (committee member).
Subjects/Keywords: Ductile Fracture; Magnesium
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APA ·
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MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Kondori, B. (2015). Ductile Fracture of Magnesium Alloys: Characterization and Modeling. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155053
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kondori, Babak. “Ductile Fracture of Magnesium Alloys: Characterization and Modeling.” 2015. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/155053.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kondori, Babak. “Ductile Fracture of Magnesium Alloys: Characterization and Modeling.” 2015. Web. 17 Feb 2020.
Vancouver:
Kondori B. Ductile Fracture of Magnesium Alloys: Characterization and Modeling. [Internet] [Thesis]. Texas A&M University; 2015. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/155053.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kondori B. Ductile Fracture of Magnesium Alloys: Characterization and Modeling. [Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155053
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
27.
Lee, Chin-Fu.
Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films.
Degree: 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155256
► Characterization of mode-I fracture toughness of ductile polymeric thin films is nontrivial. In order to gain understanding about the fracture mechanics and the processing-structure-property relationships…
(more)
▼ Characterization of mode-I
fracture toughness of ductile polymeric thin films is nontrivial. In order to gain understanding about the
fracture mechanics and the processing-structure-property relationships of metallocene linear low-density polyethylene (m-LLDPE) thin film, a custom-built double-edge notched tensile (DENT) test fixture was developed to perform the mode-I
fracture test on m-LLDPE thin films, and the essential work of
fracture (EWF) analysis, which employs an unique energy partitioning concept, was used to characterize the
fracture toughness of the thin films. Effects of specimen geometry, strain rate, film orientation, processing parameters, and resin densities on the specific essential work of
fracture, we, and the specific non-essential work of
fracture, wp, were investigated. The usefulness of the methodology incorporating the EWF analysis and the custom-built film fixture for characterizing LLDPE
fracture toughness is evaluated and discussed, and the correlations between the EWF parameters and the films? Elmendorf tear properties were also made. The visual, full-field stress distributions of the EWF film specimens were measured in-situ during mode-I facture testing by the photoelastic method, and the deformation in the process zone of post-mortem specimen was also characterized. A new experimental approach has been developed to directly quantify and partition the total mode-I
fracture energy of m-LLDPE blown films. Three distinctive deformation zones have been identified from the photoelastic observation of the m-LLDPE blown films during the mode-I facture testing. These three zones include the essential work zone due to necking and crack propagation, the non-essential plastic deformation zone, and a newly proposed recoverable viscoelastic deformation zone. The tensile true stress-strain curves of m-LLDPE blown films and the full-field strain mapping of the mode-I DENT specimen were generated to allow for quantitative energy partitioning at each deformation zone in-situ as defined by the EWF approach. The current approach allows to perform directly quantification and partitioning of the total mode-I
fracture energy for the exact physical interpretation of the EWF parameters and their correlation to material characteristics.
Advisors/Committee Members: Su, Hung-Jue (advisor), Bergbreiter, David E (committee member), Lutkenhaus, Jodie (committee member), Creasy, Terry (committee member).
Subjects/Keywords: fracture toughness; polyolefin
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APA ·
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CSE |
Export
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Manager
APA (6th Edition):
Lee, C. (2015). Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155256
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lee, Chin-Fu. “Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films.” 2015. Thesis, Texas A&M University. Accessed February 17, 2020.
http://hdl.handle.net/1969.1/155256.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lee, Chin-Fu. “Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films.” 2015. Web. 17 Feb 2020.
Vancouver:
Lee C. Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films. [Internet] [Thesis]. Texas A&M University; 2015. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969.1/155256.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lee C. Tensile True Stress - Strain Curves and Essential Work of Fracture Analysis of Polyethylene Blown Films. [Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155256
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Hong Kong
28.
Chen, Hongniao.
Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials.
Degree: PhD, 2013, University of Hong Kong
URL: Chen,
H.
[陈红鸟].
(2013).
Incremental
displacement
collocation
method
for
the
determination
of
fracture
properties
of
quasi-brittle
materials.
(Thesis).
University
of
Hong
Kong,
Pokfulam,
Hong
Kong
SAR.
Retrieved
from
http://dx.doi.org/10.5353/th_b4979944
;
http://dx.doi.org/10.5353/th_b4979944
;
http://hdl.handle.net/10722/181510
► This thesis presents experimental and numerical investigations on the fracture properties of quasi-brittle materials, including mortar, concrete and graphite. Fracture toughness in terms of the…
(more)
▼ This thesis presents experimental and numerical
investigations on the
fracture properties of quasi-brittle
materials, including mortar, concrete and graphite.
Fracture
toughness in terms of the critical stress intensity factor K_IC and
fracture energy G_F of the materials were determined through
three-point bending tests on centre-notched beams. Furthermore,
full-field displacement of the beams subjected to bend was obtained
using Electronic Speckle Pattern Interferometry (ESPI) technique.
In order to verify the accuracy of the displacement data measured
using the ESPI technique and to obtain reliable deformation
information, the displacement and strain errors induced by the
rigid-body motions of the specimen were quantified. This study
found that the displacement errors were negligible whereas the
strain errors were notable and must be eliminated. The influence of
different rigid-body motions was analyzed. It was found that the
out-of-plane movement of the specimen was critical and affected
considerably the accuracy of strain data. Thus the experimental
setup was improved accordingly to eliminate the influence of
critical rigid-body motions.
Quasi-brittle materials have a
finite stress region near the crack tip, known as the
fracture
process zone (FPZ). The materials exhibit nonlinear
fracture
behaviour in the FPZ. The cohesive crack model (CCM) is widely used
to characterize the nonlinear
fracture behaviour of quasi-brittle
materials. According to the CCM, all the nonlinear behaviours in
the FPZ can be represented by a cohesive crack, and the crack
propagation is controlled by the relationship between the cohesive
stress and crack opening, namely, the tension softening curve
(TSC). Thus an accurate estimation of the TSC is essential.
In
order to determine the TSC of quasi-brittle materials, an
incremental displacement collocation method (IDCM) was originally
developed in this study. In the IDCM, the deformation data measured
by the ESPI sensor was analyzed to obtain the crack opening
displacement (COD) of the notched specimens. The experimental COD
profiles together with the CCM were then integrated into a finite
element model to simulate the nonlinear
fracture response of the
specimen. By minimizing the difference between the computed and
measured displacements at selected collocation points, the cohesive
stress corresponding to certain crack opening was determined. The
entire TSC was constructed in a step-by-step manner following the
loading steps.
The IDCM was first applied to estimate the TSC of
mortar. By using the estimated TSC, the displacements of the
specimen under certain loading levels were computed. By comparing
the computed displacements with the experimental data, the
reliability of the IDCM and the accuracy of the estimated TSC were
verified.
The application of the IDCM was further extended to
the determination of the TSCs of concrete and graphite. The
parameters used to define the shape of the TSC of the materials
were determined using regression analysis. The applicability of
those…
Advisors/Committee Members: Kwan, AKH, Su, KL.
Subjects/Keywords: Brittleness.; Fracture mechanics.
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❌
APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chen, H. (2013). Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials. (Doctoral Dissertation). University of Hong Kong. Retrieved from Chen, H. [陈红鸟]. (2013). Incremental displacement collocation method for the determination of fracture properties of quasi-brittle materials. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4979944 ; http://dx.doi.org/10.5353/th_b4979944 ; http://hdl.handle.net/10722/181510
Chicago Manual of Style (16th Edition):
Chen, Hongniao. “Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials.” 2013. Doctoral Dissertation, University of Hong Kong. Accessed February 17, 2020.
Chen, H. [陈红鸟]. (2013). Incremental displacement collocation method for the determination of fracture properties of quasi-brittle materials. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4979944 ; http://dx.doi.org/10.5353/th_b4979944 ; http://hdl.handle.net/10722/181510.
MLA Handbook (7th Edition):
Chen, Hongniao. “Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials.” 2013. Web. 17 Feb 2020.
Vancouver:
Chen H. Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials. [Internet] [Doctoral dissertation]. University of Hong Kong; 2013. [cited 2020 Feb 17].
Available from: Chen, H. [陈红鸟]. (2013). Incremental displacement collocation method for the determination of fracture properties of quasi-brittle materials. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4979944 ; http://dx.doi.org/10.5353/th_b4979944 ; http://hdl.handle.net/10722/181510.
Council of Science Editors:
Chen H. Incremental displacement collocation method for the
determination of fracture properties of quasi-brittle
materials. [Doctoral Dissertation]. University of Hong Kong; 2013. Available from: Chen, H. [陈红鸟]. (2013). Incremental displacement collocation method for the determination of fracture properties of quasi-brittle materials. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b4979944 ; http://dx.doi.org/10.5353/th_b4979944 ; http://hdl.handle.net/10722/181510
29.
Ma, Xiaodan.
Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs.
Degree: 2013, Texas Digital Library
URL: http://hdl.handle.net/1969;
http://hdl.handle.net/2249.1/66806
► Unconventional reservoir such as tight and shale gas reservoirs has the potential of becoming the main source of cleaner energy in the 21th century. Production…
(more)
▼ Unconventional reservoir such as tight and shale gas reservoirs has the potential of becoming the main source of cleaner energy in the 21th century. Production from these reservoirs is mainly accomplished through engineered hydraulic fracturing to generate
fracture networks that provide the gas flow pathways from the rock matrix to the production wells. While hydraulic fracturing technology has progressed considerably in the last thirty years, designing the fracturing system primarily involves judgments from a team of engineers, geoscientists and geophysicists, without taking advantage of computational tools, such as numerical optimization techniques to improve short-term and long-term reservoir production.
This thesis focuses on developing novel optimization algorithms that can be used to improve the design and implementation of hydraulic fracturing in a shale gas reservoir to increase production and the net present value of unconventional assets. In particular, we consider simultaneous perturbation stochastic approximation (SPSA) and Covariance Matrix Adaptation - Evolution Strategy (CMA-ES) algorithms, which are proven very efficient in finding nearly optimal solutions. We show that with a judicious choice of control variables (continuous or discrete) we can obtain efficient algorithms for performing hydraulic
fracture optimization in unconventional reservoirs.
To achieve this, the hydraulic
fracture production optimization problem is divided into two aspects:
fracture stages placement optimization with fix stage numbers and unknown stage numbers. After check the parameters of
fracture model that could be used to simulate future reservoir behavior with a higher degree of confidence, the
fracture stages optimization is scheduling the fracturing sequence, and adjusting the
fracture stages intensity at different locations, which is similar to well placement problem. In addition to the detailed investigation of the new optimization technique, uncertainty quantification of reservoir properties and its implications on the optimization workflow is also considered in the shale gas reservoir model. Taking into account that shale gas reservoirs are highly heterogeneous systems, stochastic optimization methods are the most suitable framework for hydraulic
fracture stages placement.
Advisors/Committee Members: Gildin, Eduardo (advisor).
Subjects/Keywords: Hydraulic Fracture Placement
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APA (6th Edition):
Ma, X. (2013). Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs. (Thesis). Texas Digital Library. Retrieved from http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66806
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ma, Xiaodan. “Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs.” 2013. Thesis, Texas Digital Library. Accessed February 17, 2020.
http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66806.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ma, Xiaodan. “Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs.” 2013. Web. 17 Feb 2020.
Vancouver:
Ma X. Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs. [Internet] [Thesis]. Texas Digital Library; 2013. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66806.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ma X. Integrated Hydraulic Fracture Placement and Design Optimization in Unconventional Gas Reservoirs. [Thesis]. Texas Digital Library; 2013. Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66806
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of New Mexico
30.
Aziz, Asadollahi.
Simulation of Fracture of Concrete Using Micropolar Peridynamics.
Degree: Civil Engineering, 2014, University of New Mexico
URL: http://hdl.handle.net/1928/24689
► The main goal of the thesis is to develop a constitutive damage model for simulating tensile fracture of concrete using the micropolar peridynamics model. Micropolar…
(more)
▼ The main goal of the thesis is to develop a constitutive damage model for simulating tensile
fracture of concrete using the micropolar peridynamics model. Micropolar peridynamics was proposed by Gerstle in 2007 as a generalization to the bond based peridynamics method introduced by Silling in 2000, which was only capable of handling materials with specific Poissons ratios. Inspired by the bilinear cohesive model in the cohesive crack approach, a new constitutive damage model is proposed to simulate the tensile
fracture of a normal-strength concrete. Laboratory experimental data for crack mouth opening displacement vs. load of notched beams, obtained by Chapman in 2011 which are of three different sizes, are used to calibrate the model. It is shown that the simulation results obtained from modeling match very well with those from laboratory experiments, and the size of the
fracture process zone, the damage, and cracking patterns are match experiment as well. As a part of the research the isotropicity of the hexagonal particle lattice , proposed by Gerstle in 2011 and used in our simulations, is shown analytically, and the critical time step of the explicit time integration method, which is used to solve the governing equations, is determined.'
Advisors/Committee Members: Gerstle, Walter Jr, Ross, Timothy Jr, Arup, Maji Jr, Gerstle, Walter Jr.
Subjects/Keywords: Peridynamics; Concrete; Fracture
Record Details
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Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Aziz, A. (2014). Simulation of Fracture of Concrete Using Micropolar Peridynamics. (Masters Thesis). University of New Mexico. Retrieved from http://hdl.handle.net/1928/24689
Chicago Manual of Style (16th Edition):
Aziz, Asadollahi. “Simulation of Fracture of Concrete Using Micropolar Peridynamics.” 2014. Masters Thesis, University of New Mexico. Accessed February 17, 2020.
http://hdl.handle.net/1928/24689.
MLA Handbook (7th Edition):
Aziz, Asadollahi. “Simulation of Fracture of Concrete Using Micropolar Peridynamics.” 2014. Web. 17 Feb 2020.
Vancouver:
Aziz A. Simulation of Fracture of Concrete Using Micropolar Peridynamics. [Internet] [Masters thesis]. University of New Mexico; 2014. [cited 2020 Feb 17].
Available from: http://hdl.handle.net/1928/24689.
Council of Science Editors:
Aziz A. Simulation of Fracture of Concrete Using Micropolar Peridynamics. [Masters Thesis]. University of New Mexico; 2014. Available from: http://hdl.handle.net/1928/24689
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Open Access Theses and Dissertations
