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University of Cambridge
1.
Kaplan, Jonathan.
Rheological methods and their application to biological systems.
Degree: PhD, 2019, University of Cambridge
URL: https://doi.org/10.17863/CAM.53661
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.810061
► Pectin is a major component of the primary plant cell wall and is known to play an important role in many physiological processes. It also…
(more)
▼ Pectin is a major component of the primary plant cell wall and is known to play an important role in many physiological processes. It also has has many uses in the food and biomedical industries as it is abundant, mechanochemically versatile and non-toxic. However, the relationship between its chemistry and mechanical properties is not fully understood. In this thesis, pectin in vitro and the pectin-rich outer cells of Arabidopsis seedlings are studied using an AFM methodology adapted from the animal rheology literature. The effects of the degree of methylation, and degree of blockiness on the viscoelastic properties of pectin are explored. Elastic and viscous properties of pectin are found to be negatively correlated with its degree of methylesterification, whilst elastic properties are positively correlated with its degree of blockiness. Mixed gels, composed of pectin with differing degrees of methylesterification are also investigated and their parameters are found to scale in accordance with their volume fraction. In vivo mechanical properties observed in the Arabidopsis hypocotyl are harder to disentangle, but a number of interesting differences between transverse and axial cell walls are observed. A modelling approach is taken, and although a model based on exponentially decaying terms is found to be adequate for the two material types studied, a fractional viscoelastic model is found to be far superior for pectin in vitro. Fractional viscoelasticity is the use of fractional differential equations for the modelling of viscoelastic phenomena. In addition to its aforementioned use for pectin, its utility is evidenced here by re-analysis of data gathered from the biomechanical literature. In spite of the apparently simple qualitative behaviours they exhibit, there are a number of unique challenges associated with the selection and fitting of fractional viscoelastic models due to their mathematical complexity. This complexity may, in part, explain why fractional viscoelasticity has seen limited use thus far, even though it captures many of the qualitative behaviours commonly observed in biomaterials. This observation led to the development of an open-source rheology analysis software package, RHEOS, which has many of the common fractional and non-fractional viscoelastic models built-in. The architecture, features and implementation specifics of RHEOS are discussed.
Subjects/Keywords: Biomechanics; Viscoelasticity; Fractional Viscoelasticity; Pectin
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APA (6th Edition):
Kaplan, J. (2019). Rheological methods and their application to biological systems. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.53661 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.810061
Chicago Manual of Style (16th Edition):
Kaplan, Jonathan. “Rheological methods and their application to biological systems.” 2019. Doctoral Dissertation, University of Cambridge. Accessed March 04, 2021.
https://doi.org/10.17863/CAM.53661 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.810061.
MLA Handbook (7th Edition):
Kaplan, Jonathan. “Rheological methods and their application to biological systems.” 2019. Web. 04 Mar 2021.
Vancouver:
Kaplan J. Rheological methods and their application to biological systems. [Internet] [Doctoral dissertation]. University of Cambridge; 2019. [cited 2021 Mar 04].
Available from: https://doi.org/10.17863/CAM.53661 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.810061.
Council of Science Editors:
Kaplan J. Rheological methods and their application to biological systems. [Doctoral Dissertation]. University of Cambridge; 2019. Available from: https://doi.org/10.17863/CAM.53661 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.810061

University of Cambridge
2.
Kaplan, Jonathan.
Rheological Methods and Their Application To Biological Systems.
Degree: PhD, 2019, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/306581
► Pectin is a major component of the primary plant cell wall and is known to play an important role in many physiological processes. It also…
(more)
▼ Pectin is a major component of the primary plant cell wall and is known to play an important role in many physiological processes. It also has has many uses in the food and biomedical industries as it is abundant, mechanochemically versatile and non-toxic. However, the relationship between its chemistry and mechanical properties is not fully understood. In this thesis, pectin in vitro and the pectin-rich outer cells of Arabidopsis seedlings are studied using an AFM methodology adapted from the animal rheology literature. The effects of the degree of methylation, and degree of blockiness on the viscoelastic properties of pectin are explored. Elastic and viscous properties of pectin are found to be negatively correlated with its degree of methylesterification, whilst elastic properties are positively correlated with its degree of blockiness. Mixed gels, composed of pectin with differing degrees of methylesterification are also investigated and their parameters are found to scale in accordance with their volume fraction. In vivo mechanical properties observed in the Arabidopsis hypocotyl are harder to disentangle, but a number of interesting differences between transverse and axial cell walls are observed. A modelling approach is taken, and although a model based on exponentially decaying terms is found to be adequate for the two material types studied, a fractional viscoelastic model is found to be far superior for pectin in vitro. Fractional viscoelasticity is the use of fractional differential equations for the modelling of viscoelastic phenomena. In addition to its aforementioned use for pectin, its utility is evidenced here by re-analysis of data gathered from the biomechanical literature. In spite of the apparently simple qualitative behaviours they exhibit, there are a number of unique challenges associated with the selection and fitting of fractional viscoelastic models due to their mathematical complexity. This complexity may, in part, explain why fractional viscoelasticity has seen limited use thus far, even though it captures many of the qualitative behaviours commonly observed in biomaterials. This observation led to the development of an open-source rheology analysis software package, RHEOS, which has many of the common fractional and non-fractional viscoelastic models built-in. The architecture, features and implementation specifics of RHEOS are discussed.
Subjects/Keywords: Biomechanics; Viscoelasticity; Fractional Viscoelasticity; Pectin
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Kaplan, J. (2019). Rheological Methods and Their Application To Biological Systems. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/306581
Chicago Manual of Style (16th Edition):
Kaplan, Jonathan. “Rheological Methods and Their Application To Biological Systems.” 2019. Doctoral Dissertation, University of Cambridge. Accessed March 04, 2021.
https://www.repository.cam.ac.uk/handle/1810/306581.
MLA Handbook (7th Edition):
Kaplan, Jonathan. “Rheological Methods and Their Application To Biological Systems.” 2019. Web. 04 Mar 2021.
Vancouver:
Kaplan J. Rheological Methods and Their Application To Biological Systems. [Internet] [Doctoral dissertation]. University of Cambridge; 2019. [cited 2021 Mar 04].
Available from: https://www.repository.cam.ac.uk/handle/1810/306581.
Council of Science Editors:
Kaplan J. Rheological Methods and Their Application To Biological Systems. [Doctoral Dissertation]. University of Cambridge; 2019. Available from: https://www.repository.cam.ac.uk/handle/1810/306581

Oregon State University
3.
Jenkins, Christopher H. M.
Transient nonlinear deformations of viscoelastic membranes.
Degree: PhD, Mechanical Engineering, 1991, Oregon State University
URL: http://hdl.handle.net/1957/20302
Subjects/Keywords: Viscoelasticity
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APA ·
Chicago ·
MLA ·
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APA (6th Edition):
Jenkins, C. H. M. (1991). Transient nonlinear deformations of viscoelastic membranes. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/20302
Chicago Manual of Style (16th Edition):
Jenkins, Christopher H M. “Transient nonlinear deformations of viscoelastic membranes.” 1991. Doctoral Dissertation, Oregon State University. Accessed March 04, 2021.
http://hdl.handle.net/1957/20302.
MLA Handbook (7th Edition):
Jenkins, Christopher H M. “Transient nonlinear deformations of viscoelastic membranes.” 1991. Web. 04 Mar 2021.
Vancouver:
Jenkins CHM. Transient nonlinear deformations of viscoelastic membranes. [Internet] [Doctoral dissertation]. Oregon State University; 1991. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1957/20302.
Council of Science Editors:
Jenkins CHM. Transient nonlinear deformations of viscoelastic membranes. [Doctoral Dissertation]. Oregon State University; 1991. Available from: http://hdl.handle.net/1957/20302

Michigan State University
4.
Marvin, Eugene Lawrence, 1935-.
Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space.
Degree: PhD, Department of Metallurgy, Mechanics, and Materials Science, 1971, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:35417
Subjects/Keywords: Viscoelasticity
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Marvin, Eugene Lawrence, 1. (1971). Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space. (Doctoral Dissertation). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:35417
Chicago Manual of Style (16th Edition):
Marvin, Eugene Lawrence, 1935-. “Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space.” 1971. Doctoral Dissertation, Michigan State University. Accessed March 04, 2021.
http://etd.lib.msu.edu/islandora/object/etd:35417.
MLA Handbook (7th Edition):
Marvin, Eugene Lawrence, 1935-. “Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space.” 1971. Web. 04 Mar 2021.
Vancouver:
Marvin, Eugene Lawrence 1. Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space. [Internet] [Doctoral dissertation]. Michigan State University; 1971. [cited 2021 Mar 04].
Available from: http://etd.lib.msu.edu/islandora/object/etd:35417.
Council of Science Editors:
Marvin, Eugene Lawrence 1. Quasi-static deformation of a viscoelastic plate supported on a porous elastic fluid-filled half-space. [Doctoral Dissertation]. Michigan State University; 1971. Available from: http://etd.lib.msu.edu/islandora/object/etd:35417

Michigan State University
5.
DeLeeuw, Samuel Leonard.
Behavior of viscoelastic plates under the action of in-plane forces.
Degree: PhD, 1961, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:17760
Subjects/Keywords: Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
DeLeeuw, S. L. (1961). Behavior of viscoelastic plates under the action of in-plane forces. (Doctoral Dissertation). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:17760
Chicago Manual of Style (16th Edition):
DeLeeuw, Samuel Leonard. “Behavior of viscoelastic plates under the action of in-plane forces.” 1961. Doctoral Dissertation, Michigan State University. Accessed March 04, 2021.
http://etd.lib.msu.edu/islandora/object/etd:17760.
MLA Handbook (7th Edition):
DeLeeuw, Samuel Leonard. “Behavior of viscoelastic plates under the action of in-plane forces.” 1961. Web. 04 Mar 2021.
Vancouver:
DeLeeuw SL. Behavior of viscoelastic plates under the action of in-plane forces. [Internet] [Doctoral dissertation]. Michigan State University; 1961. [cited 2021 Mar 04].
Available from: http://etd.lib.msu.edu/islandora/object/etd:17760.
Council of Science Editors:
DeLeeuw SL. Behavior of viscoelastic plates under the action of in-plane forces. [Doctoral Dissertation]. Michigan State University; 1961. Available from: http://etd.lib.msu.edu/islandora/object/etd:17760

University of Illinois – Urbana-Champaign
6.
Zhang, Jun.
Scale-dependent homogenization of elastic-viscoelastic random composites.
Degree: PhD, Theoretical & Applied Mechans, 2017, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/98186
► Microstructural randomness is one of the most basic characteristics of nearly all solid materials and plays a key role in the prediction of their macroscopic…
(more)
▼ Microstructural randomness is one of the most basic characteristics of nearly all solid materials and plays a key role in the prediction of their macroscopic properties. Evidently, any material that displays heterogeneity on a micro scale has properties depending on the scale of approximating continuum. The key issue, which commonly arises when dealing with structure-property relations of such materials, is the validity of separation of scales of the continuum mechanical model d < L
RVE < L macro. Here L
RVE refers to the size of so-called Representative Volume Element (RVE), while d is the microstructural scale (microconstituents’ size) and Lmacro is the macroscale. In the randomly structured media, the RVE is considered to contain a sufficiently large number of micro constituents (e.g. inclusions) so that the volume can be regarded as statistically homogeneous and structurally typical of the mixture.
This research focuses on the investigation of the scale-dependent homogenization from a Statistical Volume Element (SVE) (i.e., mesoscale level) to a Representative Volume Element (RVE) (i.e., macroscale level) for linear viscoelastic random composites with perfectly bonded microconstituents. The theoretical framework employed is based on the Hill-Mandel homogenization condition, with adoption to constitutive relations including time derivative for viscoelastic materials. Requiring the material statistics to be spatially homogeneous and ergodic, the mesoscale bounds are obtained by taking the ensemble average of two stochastic initial-boundary value problems set up, respectively, under uniform kinematic and traction boundary conditions. Convergence of mesoscale responses as the scale approaches that of RVE is proved using the extended minimum theorem in
viscoelasticity and also numerically verified in both time and frequency domains through computational mechanics of planar random microstructures. The frequency-dependent scaling to RVE is further described through a complex-valued scaling function, which generalizes the concept originally developed for linear elastic random composites. This scaling function is shown to apply for all different phase combinations and essentially, uniquely characterizes the geometric effects of the microstructure in the homogenization trend from SVE to RVE.
The transition between elasticity and
viscoelasticity in elastic-viscoelastic random composites is also investigated by simulating the microstructures responses at various volume fractions of the viscoelastic phase. Systems with a significantly high contrast between the elastic and viscoelastic phase are being considered. For the random checkerboard, a sharp transition in the microstructures response occurs at the volume fraction 0.4, with the response transitioning from a time-independent type to time-dependent type. This critical volume fraction is consistent with the probability threshold of site percolation and the transition indicates a shift of dominance of one phase over the other.
Fractional calculus models are…
Advisors/Committee Members: Ostoja-Starzewski, Martin (advisor), Ostoja-Starzewski, Martin (Committee Chair), Hilgenfeldt, Sascha (committee member), Hilton, Harry H (committee member), Hutchens, Shelby B (committee member), Smith, Kyle (committee member).
Subjects/Keywords: Random composites; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, J. (2017). Scale-dependent homogenization of elastic-viscoelastic random composites. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/98186
Chicago Manual of Style (16th Edition):
Zhang, Jun. “Scale-dependent homogenization of elastic-viscoelastic random composites.” 2017. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 04, 2021.
http://hdl.handle.net/2142/98186.
MLA Handbook (7th Edition):
Zhang, Jun. “Scale-dependent homogenization of elastic-viscoelastic random composites.” 2017. Web. 04 Mar 2021.
Vancouver:
Zhang J. Scale-dependent homogenization of elastic-viscoelastic random composites. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2017. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2142/98186.
Council of Science Editors:
Zhang J. Scale-dependent homogenization of elastic-viscoelastic random composites. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2017. Available from: http://hdl.handle.net/2142/98186

University of Melbourne
7.
MOHD YUSOF, NOR SAADAH.
Ultrasonic modification of micelle structures.
Degree: 2015, University of Melbourne
URL: http://hdl.handle.net/11343/54635
► The tremendous attention given to micelle systems is due to its potential uses in many scientific, biomedical and industrial applications. Micellar aggregations possess unique ability…
(more)
▼ The tremendous attention given to micelle systems is due to its potential uses in many scientific, biomedical and industrial applications. Micellar aggregations possess unique ability to exhibit different physicochemical properties owing to their dynamic and reversible structural transformation. This flexibility is controllable by different stimuli. In this study, the possibility of designing a variety of micelle nanostructures using ultrasound is investigated. Using ultrasound as a stimulus is an advantage as it eliminates the needs of adding external chemicals to the micellar system, and experimental parameters could be easily controlled. The fundamental properties of micelles and various forces generated by ultrasound in liquids are discussed in Chapter 1.
The second chapter on Literature Review is structured in line with Results and Discussion chapters. In the first section, the use of a fluorescence based technique for the determination of critical micelle concentration as well as reported attempts in monitoring micelle structural changes are outlined. In the second section, literature dealing with structural changes in micelle systems by different stimuli is reviewed. The Reptation Reaction Model is discussed in detail in the following section. This section provides theoretical arguments on the reptation process of micelle, as well as the different reaction (recombination) routes that result in the formation of different structures of micelle. In the last section, sonochemical synthesis of gold nanoparticles is reviewed.
In Chapter 3, materials used, solution preparation methods, experimental approaches and analytical methods used are described. The micelle used in this study is cetyltrimethylammonium salicylate (CTASal) prepared by an ion exchange process between cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal). The ultrasonic settings chosen include different sonication reactors, frequency and applied power.
In Chapter 4, a fluorescence based technique using fluorescein isothiocyanate (FITC) as a probe to monitor structural changes in micelle was successfully implemented. The method was found to be successful in detecting the critical micelle concentration (cmc) as well as for monitoring the concentration dependent structural growth of CTAB micelle system. It was then tested to the sonicated CTASal micelle system. The limitation of this technique is also discussed in this chapter.
In Chapter 5, the first ultrasound-driven transformation of CTASal micelle structures is reported. The wormlike micelle formed from CTAB and NaSal was chosen due to the increasing interest of such viscoelastic micelles in recent technological applications. The sonication was carried out with a plate-type transducer at 211 kHz frequency. The wormlike micelle was found to transform to long threadlike micelle and vesicles/tubular micelle, simultaneously. These were confirmed by the cryo-TEM and rheological measurements. A mechanism for ultrasound induced micelle structural changes is proposed based on…
Subjects/Keywords: ultrasound; micelle; viscoelasticity
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
MOHD YUSOF, N. S. (2015). Ultrasonic modification of micelle structures. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/54635
Chicago Manual of Style (16th Edition):
MOHD YUSOF, NOR SAADAH. “Ultrasonic modification of micelle structures.” 2015. Doctoral Dissertation, University of Melbourne. Accessed March 04, 2021.
http://hdl.handle.net/11343/54635.
MLA Handbook (7th Edition):
MOHD YUSOF, NOR SAADAH. “Ultrasonic modification of micelle structures.” 2015. Web. 04 Mar 2021.
Vancouver:
MOHD YUSOF NS. Ultrasonic modification of micelle structures. [Internet] [Doctoral dissertation]. University of Melbourne; 2015. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/11343/54635.
Council of Science Editors:
MOHD YUSOF NS. Ultrasonic modification of micelle structures. [Doctoral Dissertation]. University of Melbourne; 2015. Available from: http://hdl.handle.net/11343/54635

Cornell University
8.
Aguilo, Miguel.
Inverse Strategies For Characterization Of Material Properties.
Degree: PhD, Civil and Environmental Engineering, 2011, Cornell University
URL: http://hdl.handle.net/1813/33569
► The imaging of constitutive parameters is of interest in many science and engineering fields. Indeed, non-invasive and nondestructive techniques are used to characterize key properties…
(more)
▼ The imaging of constitutive parameters is of interest in many science and engineering fields. Indeed, non-invasive and nondestructive techniques are used to characterize key properties of a system given its response due to an external excitation. Then, assuming a priori a given model of the system, the measured response and an inverse approach are used to identify material properties. This work was undertaken in the context of identification of spatially-varying elastic and viscoelastic parameters of solids using vibroacoustics based techniques. Two optimization approaches, nongradient and gradient-based optimization, were investigated in this work. Initially, nongradient-based algorithms were preferred over gradient-based algorithms because of there ability to find global minima irrespective of initial guesses. For instance, Gaussian radial basis functions were used to construct a finite-dimensional representation of the elastic moduli. Then, an inverse approach was used to approximate the spatiallyvarying elastic moduli through the system response induced by the radiation force of ultrasound. The inverse problem was cast as an optimization problem in which a least-square error functional that quantified the misfit between the experimental and finite element representation system response is minimized by searching over a space of admissible vectors that best describe the spatial distribution of the elastic moduli. Subsequently, gradient-based optimization was preferred over nongradient-based optimization as the number of design variables increased due to the increment in computational cost. Two inverse approaches, L2-adjoint and concept of error in constitutive equation, were investigated in the context of gradient-based optimization. First, the L2-adjoint inverse approach was used to characterize spatially-varying viscoelastic properties because of its advantage to efficiently calculate the gradient of the error functional with respect to the design variables by solving the corresponding adjoint equations. The inverse problem was cast as an optimization problem in which a least-square error functional that quantified the misfit between the experimental and the finite element representation system response is minimized by searching over a space of admissible functions that best describe the spatially-varying viscoelastic properties. Given that the least-square error functional is non-convex, an inverse approach based on the concept of error in constitutive equation was investigated. The convexity property of the error in constitutive equation functionals, shown extensively for elliptic boundary value problems, reduce the sensitivity of the inverse solution to parameter initialization. The inverse problem was cast as an optimization problem in which an error in constitutive equation functional that quantified the misfit between the kinematically and dynamically admissible stress fields is minimized by searching over a space of admissible functions that best describe the spatially-varying viscoelastic properties.…
Advisors/Committee Members: Aquino, Wilkins (chair), Mukherjee, Subrata (committee member), Ingraffea, Anthony R (committee member), Bonassar, Lawrence (committee member).
Subjects/Keywords: viscoelasticity imaging; inverse problem; vibroacoustography
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Aguilo, M. (2011). Inverse Strategies For Characterization Of Material Properties. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/33569
Chicago Manual of Style (16th Edition):
Aguilo, Miguel. “Inverse Strategies For Characterization Of Material Properties.” 2011. Doctoral Dissertation, Cornell University. Accessed March 04, 2021.
http://hdl.handle.net/1813/33569.
MLA Handbook (7th Edition):
Aguilo, Miguel. “Inverse Strategies For Characterization Of Material Properties.” 2011. Web. 04 Mar 2021.
Vancouver:
Aguilo M. Inverse Strategies For Characterization Of Material Properties. [Internet] [Doctoral dissertation]. Cornell University; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1813/33569.
Council of Science Editors:
Aguilo M. Inverse Strategies For Characterization Of Material Properties. [Doctoral Dissertation]. Cornell University; 2011. Available from: http://hdl.handle.net/1813/33569

Cornell University
9.
Zhu, Haolin.
Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials.
Degree: PhD, Theoretical and Applied Mechanics, 2012, Cornell University
URL: http://hdl.handle.net/1813/29326
► Multiphase transport in unsaturated swelling porous materials involves fluid mass transport, heat transfer as well as swelling of the porous solid matrix. Neglecting the deformation…
(more)
▼ Multiphase transport in unsaturated swelling porous materials involves fluid mass transport, heat transfer as well as swelling of the porous solid matrix. Neglecting the deformation of the solid matrix can lead to erroneous results when modeling transport phenomena in porous materials. In particular, many porous materials exhibit viscoelastic effect upon wetting/drying, which can expedite or slow the transport process. This work presents modeling and simulation of two-way coupling of multiphase transport and viscoelastic large deformation of unsaturated swelling porous systems based on fundamental physics. The work includes the development of a thermomechanical theory for multiphase transport in unsaturated swelling porous media based on the Hybrid Mixture Theory (saturated systems can also be modeled as a special case of this general theory). The theory includes three phases: solid matrix, fluid and air and uses the Coleman-Noll procedure to obtain restrictions on the form of the constitutive equations. Derived relationships include, for example, a modified Darcy's law, which takes into account both Fickian and non-Fickian transport, and a viscoelastic constitutive relationship that relates the stress and strain tensors for the solid phase. A model is then developed based on this theory for isothermal conditions which involves a simple form of a differential-integral equation that governs the fluid transport and is fully coupled with the solid large deformation. Numerical implementation of this model is then presented that involves a finite element analysis of water absorption of plane sheet pasta and numerical results of sorption curves show good agreement with experimental results obtained from the literature. Importance of including viscoelastic relaxation is investigated for soaking processes of pasta. Drying of potato is also considered in this work as an important example of two-way coupling of multiphase transport and viscoelastic large deformation of the solid matrix of porous materials because during drying processes, the transition of outer surface of the material from rubbery to glassy state at low moisture content can slow or stop shrinkage of the materials, and thus
viscoelasticity plays an important role.
Advisors/Committee Members: Mukherjee, Subrata (chair), Zehnder, Alan Taylor (committee member), Datta, Ashim K (committee member).
Subjects/Keywords: Porous materials; Swelling; Viscoelasticity
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhu, H. (2012). Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/29326
Chicago Manual of Style (16th Edition):
Zhu, Haolin. “Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials.” 2012. Doctoral Dissertation, Cornell University. Accessed March 04, 2021.
http://hdl.handle.net/1813/29326.
MLA Handbook (7th Edition):
Zhu, Haolin. “Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials.” 2012. Web. 04 Mar 2021.
Vancouver:
Zhu H. Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials. [Internet] [Doctoral dissertation]. Cornell University; 2012. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1813/29326.
Council of Science Editors:
Zhu H. Two-Way Coupling Of Multiphase Transport And Viscoelastic Large Deformation Of Unsaturated Swelling Porous Materials. [Doctoral Dissertation]. Cornell University; 2012. Available from: http://hdl.handle.net/1813/29326

University of Pretoria
10.
Visagie, Amcois.
The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure.
Degree: MSc, Physiology, 2016, University of Pretoria
URL: http://hdl.handle.net/2263/61676
► 17β-Estradiol (E2) and progesterone (P4) have various important functions but the effect of these endogenous hormone concentrations on fibrin network formation has not been established.…
(more)
▼ 17β-Estradiol (E2) and progesterone (P4) have various
important functions but the effect of
these endogenous hormone
concentrations on fibrin network formation has not been
established. It is essential to understand natural hormone
mechanisms since these
hormones are still present in circulation
while hormonal contraceptives, which are
associated with increased
risk of venous thromboembolism, are used. In this study the
formation of a fibrin network is analysed when different
physiological concentrations of E2
and P4 is added to platelet
poor plasma. Blood coagulation is critical for haemostasis but
when the formation of a stable clot is influenced in such a way
that hypercoagulation takes
its course, it can have detrimental
effects as it increases the risk of venous thrombosis.
During
blood coagulation fibrinogen is converted into fibrin in the
presence of thrombin.
The formation of a dense fibrin clot
structure is quite an intense process and packaged in
very
specific ways. Both E2 and P4 has the ability to shift the
haemostatic balance to a
hypercoagulable state and therefore
viscoelastic studies, morphological analysis as well as
turbidimetry were used in this study to observe the possible
changes in the fibrin network
formation. Viscoelastic studies
included thromboelastography (TEG) which gave insight to
the
properties of clot formation. Morphological studies included
scanning electron
microscopy (SEM) and atomic force microscopy
(AFM) which delivered an investigation in
fibrin network
morphology, fibrin fiber diameter and surface roughness.
Turbidimetry
included further analysis of plasma fibrin clot
formation and clot lysis time (CLT). Results
showed that E2 and P4
showed hypercoagulable viscoelastic properties with decreased
fibrin diameter and surface roughness while increased occurrence of
dense matted deposits
(DMDs) were evident. Turbidimetry showed
decreased CLT for E2, but not P4. These results
suggest in the
presence of endogenous estrogen and progesterone, which is
associated with
hypercoagulability, the additional burden of
synthetic hormones may result in a prothrombotic
and
hypercoagulable state in females with an inflammatory
predisposition. It
appears that both E2 and P4, which are known
for their anti- and pro-inflammatory action,
may influence fibrin
network formation on a molecular level. These results are of
clinical
importance when considering hormones as either a
pathological agent or therapeutic
intervention.
Advisors/Committee Members: Swanepoel, A.C. (advisor), Pretorius, Etheresia (coadvisor).
Subjects/Keywords: UCTD;
Thromboembolism;
Progesterone;
Fibrinogen;
Viscoelasticity
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MLA ·
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to Zotero / EndNote / Reference
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APA (6th Edition):
Visagie, A. (2016). The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/61676
Chicago Manual of Style (16th Edition):
Visagie, Amcois. “The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure.” 2016. Masters Thesis, University of Pretoria. Accessed March 04, 2021.
http://hdl.handle.net/2263/61676.
MLA Handbook (7th Edition):
Visagie, Amcois. “The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure.” 2016. Web. 04 Mar 2021.
Vancouver:
Visagie A. The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure. [Internet] [Masters thesis]. University of Pretoria; 2016. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2263/61676.
Council of Science Editors:
Visagie A. The effects
of physiological concentrations of 17ß-Estradiol and Progesterone
on fibrin network ultrastructure. [Masters Thesis]. University of Pretoria; 2016. Available from: http://hdl.handle.net/2263/61676

University of Toronto
11.
van Wijk, Ernst.
Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry.
Degree: 2018, University of Toronto
URL: http://hdl.handle.net/1807/89497
► This thesis investigated the effects of polymer concentration and nozzle design on jet stability for polymeric abrasive slurry-jet channel machining in glass. Conical nozzle contractions,…
(more)
▼ This thesis investigated the effects of polymer concentration and nozzle design on jet stability for polymeric abrasive slurry-jet channel machining in glass. Conical nozzle contractions, having angles of 180°, 60°, 30°, and 20°, were used with aqueous polyethylene oxide (PEO) polymer solutions, having concentrations of 100, 200, and 300 ppm. Channels were machined in glass using slurries containing 1 wt% of 10 μm aluminum oxide particles, made from the same four working fluids used to study jet oscillation.
Jet oscillation was found to increase nonlinearly with polymer concentration for all contraction geometries. As a result of the effect of the varying degrees of jet oscillation, a clear relationship was found between the polymer concentration and the channel width. Flow visualization within the nozzle confirmed the presence of vortices that have been associated with jet instability, but did not reveal a clear reason for the changes in jet stability.
M.A.S.
Advisors/Committee Members: Spelt, Jan K, Papini, Marcello, Mechanical and Industrial Engineering.
Subjects/Keywords: Jet Oscillation; Machining; Viscoelasticity; 0548
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
van Wijk, E. (2018). Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/89497
Chicago Manual of Style (16th Edition):
van Wijk, Ernst. “Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry.” 2018. Masters Thesis, University of Toronto. Accessed March 04, 2021.
http://hdl.handle.net/1807/89497.
MLA Handbook (7th Edition):
van Wijk, Ernst. “Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry.” 2018. Web. 04 Mar 2021.
Vancouver:
van Wijk E. Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry. [Internet] [Masters thesis]. University of Toronto; 2018. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1807/89497.
Council of Science Editors:
van Wijk E. Jet Oscillation in Abrasive Slurry-Jet Machining as a Function of Polymer Concentration and Nozzle Geometry. [Masters Thesis]. University of Toronto; 2018. Available from: http://hdl.handle.net/1807/89497

Hong Kong University of Science and Technology
12.
Weerasinghe, Thilina Wijayantha.
Plantar-foot surface pressure thresholds and related viscoelastic properties.
Degree: 2015, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-78799
;
https://doi.org/10.14711/thesis-b1514446
;
http://repository.ust.hk/ir/bitstream/1783.1-78799/1/th_redirect.html
► The plantar-foot comprises viscoelastic tissue of several different layers. Previous studies have investigated properties such as Pressure Pain Threshold (PPT), Pressure Discomfort Threshold (PDT) and…
(more)
▼ The plantar-foot comprises viscoelastic tissue of several different layers. Previous studies have investigated properties such as Pressure Pain Threshold (PPT), Pressure Discomfort Threshold (PDT) and Stiffness of the plantar foot. However, only a handful of studies have evaluated the viscoelastic properties. Even though past studies have recorded the properties of the plantar-foot, it is not possible to compare the results across the studies due to testing location mismatches. In this thesis a generalizable grid was developed for the foot using anatomical landmarks. The grid had 95 points, and each point was tested using an automatic tissue tester with a 0.5 cm2 soft edge cylindrical probe at an indentation speed of 1mm/s. Reliability of the grid was tested by measuring and comparing the PPT, PDT and stiffness. Between subjects similarity of the grid was investigated using Morisita’s similarity index. PPT and PDT showed a Morisita’s similarity index value higher than 0.9 in male participants and higher than 0.75 in female participants. Spatial auto correlation was calculated using Moran’s I index. PDT and PPT had Moran's I index values of 0.7. K means clustering was used to developed maps for PPT, PDT and Stiffness over the plantar-foot surface. The perceived feeling of hardness was tested over the plantar-foot surface in another experiment. Three Ethyl Vinyl Acetate (EVA) materials of different hardness were used for the four regions of Heel, Mid-foot, Forefoot, Toes. The heel hardness had a significant (p<0.05) influence on the perceived hardness rating of the other regions. When harder materials were in the heel region, regardless of what materials were in the other regions, participants felt a higher perceived hardness and vice-versa. The viscoelastic properties of the plantar-foot skin were evaluated using F = kX + cX̍. Three indentation speeds (1 mm/s, 3 mm/s and 5 mm/s) were used to determine the mechanical properties of five different locations in the plantar-foot in East Asian and South Asian participants. The model F = kX + cX̍ fits the experimental data with a relatively high coefficient of determination (R2 > 0.84) for each subject and each testing location. Both, the testing location and the ethnic groups showed significant effects on the 'k' and the 'c' values. Indentation area dependency on 'k' and 'c' values were evaluated in another experiment with twenty-four South Asian participants using three different indentation areas at five different testing locations in the plantar-foot. The indentation area and the testing location showed significant effects on k' and 'c' values. Plantar-foot skin deformation can be modeled in the form of F = (j (A) + k)) X + (m (A) + n) X̍.; where j, k, m, n are constants at each testing location. The results can be used to develop new designs for footbeds considering gender and ethnic group differences.
Subjects/Keywords: Foot
; Pressure
; Measurement
; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Weerasinghe, T. W. (2015). Plantar-foot surface pressure thresholds and related viscoelastic properties. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-78799 ; https://doi.org/10.14711/thesis-b1514446 ; http://repository.ust.hk/ir/bitstream/1783.1-78799/1/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):
Weerasinghe, Thilina Wijayantha. “Plantar-foot surface pressure thresholds and related viscoelastic properties.” 2015. Thesis, Hong Kong University of Science and Technology. Accessed March 04, 2021.
http://repository.ust.hk/ir/Record/1783.1-78799 ; https://doi.org/10.14711/thesis-b1514446 ; http://repository.ust.hk/ir/bitstream/1783.1-78799/1/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):
Weerasinghe, Thilina Wijayantha. “Plantar-foot surface pressure thresholds and related viscoelastic properties.” 2015. Web. 04 Mar 2021.
Vancouver:
Weerasinghe TW. Plantar-foot surface pressure thresholds and related viscoelastic properties. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2015. [cited 2021 Mar 04].
Available from: http://repository.ust.hk/ir/Record/1783.1-78799 ; https://doi.org/10.14711/thesis-b1514446 ; http://repository.ust.hk/ir/bitstream/1783.1-78799/1/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:
Weerasinghe TW. Plantar-foot surface pressure thresholds and related viscoelastic properties. [Thesis]. Hong Kong University of Science and Technology; 2015. Available from: http://repository.ust.hk/ir/Record/1783.1-78799 ; https://doi.org/10.14711/thesis-b1514446 ; http://repository.ust.hk/ir/bitstream/1783.1-78799/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University
13.
Kanewske, Daniel Bert.
Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm.
Degree: PhD, College of Letters & Science, 2016, Montana State University
URL: https://scholarworks.montana.edu/xmlui/handle/1/12368
► The symmetry of the numeric representation of the stress tensor has been shown to be important for maintaining stability, in the sense of Hadamard, of…
(more)
▼ The symmetry of the numeric representation of the stress tensor has been shown to be important for maintaining stability, in the sense of Hadamard, of the numeric method. Also, the viscoelastic behavior of biofilms is well documented. A 2D model for the viscoelastic flow of a biofilm using a modified Navier-Stokes equation (NSE) with a novel elastic stress term are presented. The elastic stress is modeled using a numeric stress tensor symmetry preserving scheme that is based on the numeric solution to the Lie derivative and its equivalent counterpart in the form of a symmetric matrix Riccati differential equation (SMRDE). In addition, a coupled advection equation (AE) is applied to the biofilm volume fraction. Solutions to the NSE and AE are found by applying the finite element method (FEM) to the Eulerian-Lagrangian method (ELM). The ELM is solved by first determining the 'characteristic foot' for each Gaussian quadrature point and node point in the mesh. The advection equation is solved using a modified Galerkin Least Squares (GLS) method. Computations are made using the Trilinos iterative sparse matrix solver library called AztexOO which has built in matrix preconditioners and support for parallel processing. The resulting model is used to predict the deformation of a biofilm in a 2D channel. In addition, the accompanying distribution of the pressure and stresses over the evolving velocity field is presented.
Advisors/Committee Members: Chairperson, Graduate Committee: Tianyu Zhang (advisor).
Subjects/Keywords: Biofilms.; Mathematical models.; Viscoelasticity.
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kanewske, D. B. (2016). Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm. (Doctoral Dissertation). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/12368
Chicago Manual of Style (16th Edition):
Kanewske, Daniel Bert. “Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm.” 2016. Doctoral Dissertation, Montana State University. Accessed March 04, 2021.
https://scholarworks.montana.edu/xmlui/handle/1/12368.
MLA Handbook (7th Edition):
Kanewske, Daniel Bert. “Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm.” 2016. Web. 04 Mar 2021.
Vancouver:
Kanewske DB. Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm. [Internet] [Doctoral dissertation]. Montana State University; 2016. [cited 2021 Mar 04].
Available from: https://scholarworks.montana.edu/xmlui/handle/1/12368.
Council of Science Editors:
Kanewske DB. Stress tensor symmetry preserving model applied to the 2-D viscoelastic flow of a biofilm. [Doctoral Dissertation]. Montana State University; 2016. Available from: https://scholarworks.montana.edu/xmlui/handle/1/12368

University of Illinois – Urbana-Champaign
14.
Bharadwaj, Narayanan Ashwin Kumar.
Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites.
Degree: PhD, Mechanical Engineering, 2016, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/93007
► Viscoelastic materials, such as crosslinked networks of synthetic and biological polymers, exhibit a nonlinear rheological response to mechanical deformation. Oscillatory shear is a popular deformation…
(more)
▼ Viscoelastic materials, such as crosslinked networks of synthetic and biological polymers, exhibit a nonlinear rheological response to mechanical deformation. Oscillatory shear is a popular deformation protocol for viscoelastic characterization, both linear and nonlinear, the latter referred to as large amplitude oscillatory shear (LAOS). However, the accompanying nonlinear material response in LAOS is challenging to interpret and requires non-trivial material descriptions. The goal of this thesis is to provide a new paradigm of nonlinear rheological characterization using oscillatory shear deformation as well as to demonstrate applications of nonlinear viscoelastic materials, involving stimuli responsive polymer-colloid composites.
A nonlinear viscoelastic response in LAOS is high dimensional, covering the entire range of the 2D Pipkin space of deformation amplitude and frequency. A low-dimensional language and framework is introduced for viscoelastic characterization using asymptotic material functions in oscillatory shear, referred to as medium amplitude oscillatory shear (MAOS). These material functions, four in number, emerge from an asymptotic expansion in deformation amplitude and depend only on the oscillatory frequency. They carry physically meaningful inter- and intra-cycle information, for example, softening/stiffening and thickening/thinning of the stress response. For the first time, experimental measurements are shown for all four asymptotic nonlinearities.
Parallel disk measurements in the MAOS regime require a correction for the apparent stress response. In this regime, the derivatives appearing in the general stress correction are constant over the range of interest, and this allows exact single-point corrections for all four asymptotic nonlinearities. Experimental measurements are presented for the asymptotically-nonlinear signals on an entangled polymer melt, using both parallel disk and cone fixtures. The corrected (amplified) parallel disk signals match the measurements with the cone.
Using a fourth order fluid expansion, universal frequency scaling and interrelations are derived for asymptotic nonlinearities in the terminal regime, defined by the limit of De<<1. Experimental measurements, consistent with such predictions, are presented for an entangled polymer melt in the terminal regime. Beyond the terminal regime, at higher frequencies, signs and magnitudes cannot be universally predicted, leaving these as free parameters that depend on the specifics of the material microstructure or constitutive model.
A library of expectations of signatures (or fingerprints) is developed for all four asymptotically-nonlinear material functions for seven nonlinear constitutive models. The fingerprints are different in magnitude, frequency-scaling, curve shapes and sign changes, and distinguish the models. They obey the terminal regime inter-relations and frequency scaling, and are driven by strain-rates at small De and strains at large De. Some constitutive models exhibit multiple sign changes at…
Advisors/Committee Members: Ewoldt, Randy H (advisor), Ewoldt, Randy H (Committee Chair), Schweizer, Kenneth S (committee member), Hilgenfeldt, Sascha (committee member), Rogers, Simon (committee member).
Subjects/Keywords: Nonlinear Viscoelasticity; Stimuli-responsive materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bharadwaj, N. A. K. (2016). Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/93007
Chicago Manual of Style (16th Edition):
Bharadwaj, Narayanan Ashwin Kumar. “Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 04, 2021.
http://hdl.handle.net/2142/93007.
MLA Handbook (7th Edition):
Bharadwaj, Narayanan Ashwin Kumar. “Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites.” 2016. Web. 04 Mar 2021.
Vancouver:
Bharadwaj NAK. Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2142/93007.
Council of Science Editors:
Bharadwaj NAK. Asymptotically nonliner oscillatory shear: theory, modeling, measurements and applications of nonlinear elasticity to stimuli-responsive composites. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/93007

Texas Tech University
15.
Xu, Shanhong.
MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS.
Degree: Chemical Engineering, 2011, Texas Tech University
URL: http://hdl.handle.net/2346/ETD-TTU-2011-08-1740
► It is very important to understand the mechanical properties of polymers at the nanoscale with the continuing demand of decreasing the size of circuit in…
(more)
▼ It is very important to understand the mechanical properties of polymers at the nanoscale with the continuing demand of decreasing the size of circuit in the electronic industry. There has been considerable research on the confinement effect in thin films with a variety of techniques, often with conflicting results. Most of the previous work has been done in a pseudo-thermodynamic mode, where the glass transition temperature (Tg) is taken to be the break in the temperature dependence of a property [e.g. ellipsometry, Brillouin scattering]. A method based on the determination of a dynamic property, the absolute biaxial creep compliance, has been developed by O’Connell and McKenna. The method is a scaled down version of the classic bubble inflation technique. They found that the Tg of polystyrene (PS) decreases with film thickness, while it doesn’t change for poly(vinyl acetate) (PVAc). The most surprising finding is that the rubbery plateau compliance decreases dramatically for both materials. These results are unexplained though it has been suggested that the observed stiffening at the nanometer size scale could be attributed to surface tension.
In this thesis, we investigated a new material (poly (n-butyl methacrylate) (PBMA)) that shows significantly different behavior from PVAc or PS and that provides new evidence that the stiffening of the rubbery plateau region in ultrathin polymer films is a nanoconfinement effect. We developed the stress-strain analysis and energy balance approach to separate the surface tension contribution to the observed rubbery stiffening. We found that the surface tension contribution for PBMA is much larger than that of PVAc. The rubbery stiffening of PBMA is much less than PS and PVAc. The surface tension of PBMA doesn’t change with decreasing film thickness.
Further, the geometry effect in the nanobubble inflation technique was investigated by comparing the creep behavior of circular bubbles with that of rectangular bubbles. The accuracy of the analytical approximate solutions was evaluated by comparing with the finite element (FE) analysis for simulation of the inflation of rectangular bubbles. We found that the shape of the bubble obtained from the experiment is consistent with that of FE. We also found that the reduction of Tg and the rubbery plateau compliance for rectangular bubbles are consistent with those of circular bubbles. So geometry is not the reason for the observed stiffening effect.
Next, we investigated the molecular architecture effect in the nanobubble inflation technique by comparing the creep behavior of linear PS with that of the three-arm star PS. Both the reduction of Tg and the stiffening in the rubbery region for star PS is consistent with those of linear PS.
In the last part of this thesis, the capability of the nanobubble inflation technique to investigate the yield and fracture behavior of ultrathin films was demonstrated. Stepped pressure is applied to ultrathin films until it broke. We found that for 33nm film, it transit from brittle failure to…
Advisors/Committee Members: McKenna, Gregory B. (Committee Chair), Simon, Sindee L. (committee member), Weeks, Brandon L. (committee member), Quitevis, Edward L. (committee member).
Subjects/Keywords: Nanobubble; Thin films; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Xu, S. (2011). MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS. (Thesis). Texas Tech University. Retrieved from http://hdl.handle.net/2346/ETD-TTU-2011-08-1740
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):
Xu, Shanhong. “MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS.” 2011. Thesis, Texas Tech University. Accessed March 04, 2021.
http://hdl.handle.net/2346/ETD-TTU-2011-08-1740.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Xu, Shanhong. “MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS.” 2011. Web. 04 Mar 2021.
Vancouver:
Xu S. MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS. [Internet] [Thesis]. Texas Tech University; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2346/ETD-TTU-2011-08-1740.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Xu S. MECHANICAL PROPERTIES OF ULTRATHIN POLYMER FILMS INVESTIGATED BY A NANOBUBBLE INFLATION TECHNIQUE: SURFACE TENSION, GEOMETRY AND MOLECULAR ARCHITECTURE EFFECTS. [Thesis]. Texas Tech University; 2011. Available from: http://hdl.handle.net/2346/ETD-TTU-2011-08-1740
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Georgia Tech
16.
Hafkemeyer, Hansgeorg Philipp.
Determination of the relaxation time of nonnewtonian fluids: a squeeze film application.
Degree: MS, Mechanical Engineering, 1969, Georgia Tech
URL: http://hdl.handle.net/1853/17089
Subjects/Keywords: Rheology; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Hafkemeyer, H. P. (1969). Determination of the relaxation time of nonnewtonian fluids: a squeeze film application. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/17089
Chicago Manual of Style (16th Edition):
Hafkemeyer, Hansgeorg Philipp. “Determination of the relaxation time of nonnewtonian fluids: a squeeze film application.” 1969. Masters Thesis, Georgia Tech. Accessed March 04, 2021.
http://hdl.handle.net/1853/17089.
MLA Handbook (7th Edition):
Hafkemeyer, Hansgeorg Philipp. “Determination of the relaxation time of nonnewtonian fluids: a squeeze film application.” 1969. Web. 04 Mar 2021.
Vancouver:
Hafkemeyer HP. Determination of the relaxation time of nonnewtonian fluids: a squeeze film application. [Internet] [Masters thesis]. Georgia Tech; 1969. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1853/17089.
Council of Science Editors:
Hafkemeyer HP. Determination of the relaxation time of nonnewtonian fluids: a squeeze film application. [Masters Thesis]. Georgia Tech; 1969. Available from: http://hdl.handle.net/1853/17089

University of Waterloo
17.
Charbonneau, Linda.
Time-Dependent Tensile Properties of ETFE Foils.
Degree: 2011, University of Waterloo
URL: http://hdl.handle.net/10012/6190
► The purpose of this thesis is to provide an overview of ETFE foil, as it applies to pneumatic cushion cladding, with a focus on creep…
(more)
▼ The purpose of this thesis is to provide an overview of ETFE foil, as it applies to pneumatic cushion cladding, with a focus on creep behavior of the material.
Characteristics of ETFE, including weight, optics, insulation, flexibility, environmental properties, fire performance, cushion span and other features are discussed, and, where possible, are compared to the characteristics of glass panels used in similar applications. Relevant chemical and mechanical properties of ETFE are given. Load carrying concepts of tension structures and inflated cushions are discussed, as well as structural design methods for ETFE cushions. Several prominent structures constructed using ETFE foil are introduced and benefits and design issues associated with these structures are reviewed.
When used in cushion applications, ETFE films are placed in constant tension, and are therefore subject to creep. Quantifying this creep is desirable so that it can be predicted during the design phase. Therefore, this thesis summarizes the findings of other researchers in the area of creep of ETFE as well as the general mechanical behavior of the material, and presents the results of uniaxial creep tests done for the purpose of this study. These tests included 24 hour uniaxial creep tests done at four stress levels on both the transverse and longitudinal directions of three different brands of film. Two thicknesses of the third film were acquired and both were tested. The stress levels were chosen to coincide with typical design tensile stresses for ETFE film, and to be similar to the levels tested by other researchers. The effects of the different stresses, brands, directions and thicknesses are evaluated and discussed. Three seven day creep tests were also done on one of the films, each at a different stress level.
Constitutive viscoelastic and viscoplastic models were developed to represent the 24-hour creep data. The viscoelastic models were based on a four-element Kelvin model and the viscoplastic models were based on a power-law model. The model parameters were determined from the data using linear least squares fitting. Models were also developed for the seven day creep data. Several of these models were based only upon the first 24 hours of data, and were used to determine the applicability of the 24-hour creep models to long-term behavior. It was found that while a viscoelastic model appears to fit long-term creep most closely, the 24-hour models are inadequate for modeling longer time frames. Another method is required for predicting long-term creep. Nonlinear fitting of the parameters is recommended as a possible alternative for creating more accurate models. Longer-term creep tests are also recommended.
Tensile tests were also done on the films to confirm mechanical properties supplied by the film manufacturers. Good agreement to the given values was found in the test data.
Subjects/Keywords: ETFE; Creep; Tension Structures; Viscoelasticity
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APA ·
Chicago ·
MLA ·
Vancouver ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Charbonneau, L. (2011). Time-Dependent Tensile Properties of ETFE Foils. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/6190
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):
Charbonneau, Linda. “Time-Dependent Tensile Properties of ETFE Foils.” 2011. Thesis, University of Waterloo. Accessed March 04, 2021.
http://hdl.handle.net/10012/6190.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Charbonneau, Linda. “Time-Dependent Tensile Properties of ETFE Foils.” 2011. Web. 04 Mar 2021.
Vancouver:
Charbonneau L. Time-Dependent Tensile Properties of ETFE Foils. [Internet] [Thesis]. University of Waterloo; 2011. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/10012/6190.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Charbonneau L. Time-Dependent Tensile Properties of ETFE Foils. [Thesis]. University of Waterloo; 2011. Available from: http://hdl.handle.net/10012/6190
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Louisiana State University
18.
Regmi, Bishnu Prasad.
GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors.
Degree: PhD, Chemistry, 2014, Louisiana State University
URL: etd-07082014-173616
;
https://digitalcommons.lsu.edu/gradschool_dissertations/3323
► There has been an ever-increasing demand for the development of high-performance sensing devices for detection and discrimination of volatile organic compounds (VOCs) present in different…
(more)
▼ There has been an ever-increasing demand for the development of high-performance sensing devices for detection and discrimination of volatile organic compounds (VOCs) present in different environments. Among a number of sensing devices currently available, sorption-based sensors are particularly attractive because they are simple and inexpensive, require low power, and are appropriate for fabrication of multisensor arrays. A sorption-based sensor is comprised of a chemically active coating immobilized on the surface of a physical transducer. The chemically active film interacts with analytes, and the transducer converts the binding event into an electrical signal. This dissertation is focused on a sorption-based sensor prepared by using ionic liquids (ILs) and a group of uniform materials based on organic salts (GUMBOS) as the sensing materials and the quartz crystal microbalance (QCM) as the transducer. ILs are defined as organic salts which melt below 100 °C, and similar organic salts with melting point between 25 and 250 °C are defined as GUMBOS. In this research, a series of films comprising binary blends of an IL (or GUMBOS) and polymer are deposited onto the QCM surface in order to evaluate their vapor-sensing characteristics. The QCM sensors on exposure to organic vapors displayed a change in frequency and motional resistance, and both of these parameters were simultaneously measured. Examination of the data revealed an interesting relationship between the QCM parameters and the molecular weight of the absorbed vapors. The initial findings are reported in Chapter 2 of this dissertation. Additional studies were conducted in an effort to fully understand the interesting behavior of this type of material. More elaborate studies along with the theoretical rationale for the relationship between the QCM parameters and the molecular weight of vapors are presented in Chapter 3. Another important aspect of this dissertation is the design of highly sensitive materials for vapor-sensing applications. Toward this end, two representative GUMBOS were synthesized using porphyrin and phthalocyanine derivatives. The QCM device coated with these GUMBOS exhibited a rapid response and high sensitivity toward different organic vapors. Altogether, these studies demonstrate the true potential of this type of materials for vapor-sensing applications.
Subjects/Keywords: Viscoelasticity; Maxwell; Modeling; QCM-D
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Regmi, B. P. (2014). GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-07082014-173616 ; https://digitalcommons.lsu.edu/gradschool_dissertations/3323
Chicago Manual of Style (16th Edition):
Regmi, Bishnu Prasad. “GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors.” 2014. Doctoral Dissertation, Louisiana State University. Accessed March 04, 2021.
etd-07082014-173616 ; https://digitalcommons.lsu.edu/gradschool_dissertations/3323.
MLA Handbook (7th Edition):
Regmi, Bishnu Prasad. “GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors.” 2014. Web. 04 Mar 2021.
Vancouver:
Regmi BP. GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors. [Internet] [Doctoral dissertation]. Louisiana State University; 2014. [cited 2021 Mar 04].
Available from: etd-07082014-173616 ; https://digitalcommons.lsu.edu/gradschool_dissertations/3323.
Council of Science Editors:
Regmi BP. GUMBOS- and Ionic Liquid-Coated Quartz Crystal Microbalance Sensors for Detection and Molecular Weight Determination of Organic Vapors. [Doctoral Dissertation]. Louisiana State University; 2014. Available from: etd-07082014-173616 ; https://digitalcommons.lsu.edu/gradschool_dissertations/3323

University of Texas – Austin
19.
Xu, Qinwu.
Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements.
Degree: PhD, Civil Engineering, 2014, University of Texas – Austin
URL: http://hdl.handle.net/2152/25943
► Most existing computational methods for inverting material properties of multilayer systems have focused primarily on elastic properties of materials or a static approach. Typically, they…
(more)
▼ Most existing computational methods for inverting material properties of multilayer systems have focused primarily on elastic properties of materials or a static approach. Typically, they are based on a two-stage approach: (I) modeling structural responses with a computer program, and (II) estimating layer properties mathematically using the response outputs determined in stage I without interactions with the governing state partial-differential-equation (PDE) of stage I. This two-stage approach may not be accurate and efficient enough for inverting larger scale model parameters. The objective of this research was to develop a computational method to invert dynamic moduli of multilayer systems with applications to flexible pavements under falling weight deflectometer (FWD) tests, thereby advancing existing methods and fostering understanding of material behaviors. This research first developed a finite-element and Newton-Raphson method to invert layer elastic moduli using FWD data. The model improved the moduli seeds estimation and achieved a satisfactory accuracy based on Monte Carlo simulations, addressing the common back-calculation issue of no unique solutions. Consequently, a time-domain finite-element method was developed to simulate dynamic-viscoelastic responses of the multilayer systems under loading pulses. Simulation results demonstrated that the dynamic-viscoelastic-damping-coupled model could emulate structural responses more accurately, thereby advancing existing simulation approaches. By using the dynamic-viscoelastic-response model as one computation module, this research led to the development of a PDE-constrained Lagrangian optimization method to invert dynamic moduli and viscoelastic properties of multilayer systems. The Lagrangian function was used as an objective function, with a regularization term and governing-state PDE constraint. Both the first-order (gradient) and second-order variation (Hessian matrix) of the Lagrangian were computed to satisfy necessary and sufficient optimality conditions, and Armijo rule was modified to determine a stable step length. The developed method improved computation speed significantly, and it is superior for large-scale inverse problems. The model was implemented for evaluating flexible pavements under FWD tests and for inverting the master curve of dynamic moduli of the asphalt layer. Independent computer coding was developed for all numerical methods. The computational methods developed may also be applied to other multilayer systems, such as tissues and sandwich structures at different time and length scales.
Advisors/Committee Members: Prozzi, Jorge Alberto (advisor).
Subjects/Keywords: Inverse method; Viscoelasticity; Multilayer
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Xu, Q. (2014). Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/25943
Chicago Manual of Style (16th Edition):
Xu, Qinwu. “Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements.” 2014. Doctoral Dissertation, University of Texas – Austin. Accessed March 04, 2021.
http://hdl.handle.net/2152/25943.
MLA Handbook (7th Edition):
Xu, Qinwu. “Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements.” 2014. Web. 04 Mar 2021.
Vancouver:
Xu Q. Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2014. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/2152/25943.
Council of Science Editors:
Xu Q. Development of a computational method for inverting dynamic moduli of multilayer systems with applications to flexible pavements. [Doctoral Dissertation]. University of Texas – Austin; 2014. Available from: http://hdl.handle.net/2152/25943

The Ohio State University
20.
Pandalai, Krishnan Ravi Varman, 1933-.
Time dependent behavior of a viscoslastic polymeric material
.
Degree: PhD, Graduate School, 1975, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486998116226737
Subjects/Keywords: Engineering; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pandalai, Krishnan Ravi Varman, 1. (1975). Time dependent behavior of a viscoslastic polymeric material
. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1486998116226737
Chicago Manual of Style (16th Edition):
Pandalai, Krishnan Ravi Varman, 1933-. “Time dependent behavior of a viscoslastic polymeric material
.” 1975. Doctoral Dissertation, The Ohio State University. Accessed March 04, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1486998116226737.
MLA Handbook (7th Edition):
Pandalai, Krishnan Ravi Varman, 1933-. “Time dependent behavior of a viscoslastic polymeric material
.” 1975. Web. 04 Mar 2021.
Vancouver:
Pandalai, Krishnan Ravi Varman 1. Time dependent behavior of a viscoslastic polymeric material
. [Internet] [Doctoral dissertation]. The Ohio State University; 1975. [cited 2021 Mar 04].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486998116226737.
Council of Science Editors:
Pandalai, Krishnan Ravi Varman 1. Time dependent behavior of a viscoslastic polymeric material
. [Doctoral Dissertation]. The Ohio State University; 1975. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486998116226737

The Ohio State University
21.
Chandrangsu, Karoon.
A finite element formulation for nonlinear viscoelastic
analysis.
Degree: PhD, Graduate School, 1976, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1487004443403503
Subjects/Keywords: Engineering; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chandrangsu, K. (1976). A finite element formulation for nonlinear viscoelastic
analysis. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1487004443403503
Chicago Manual of Style (16th Edition):
Chandrangsu, Karoon. “A finite element formulation for nonlinear viscoelastic
analysis.” 1976. Doctoral Dissertation, The Ohio State University. Accessed March 04, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1487004443403503.
MLA Handbook (7th Edition):
Chandrangsu, Karoon. “A finite element formulation for nonlinear viscoelastic
analysis.” 1976. Web. 04 Mar 2021.
Vancouver:
Chandrangsu K. A finite element formulation for nonlinear viscoelastic
analysis. [Internet] [Doctoral dissertation]. The Ohio State University; 1976. [cited 2021 Mar 04].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1487004443403503.
Council of Science Editors:
Chandrangsu K. A finite element formulation for nonlinear viscoelastic
analysis. [Doctoral Dissertation]. The Ohio State University; 1976. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1487004443403503

The Ohio State University
22.
Jackimiak, Paul Daniel.
Time-dependent, non-Newtonian behavior of viscoelastic
materials.
Degree: PhD, Graduate School, 1971, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486722980193887
Subjects/Keywords: Engineering; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jackimiak, P. D. (1971). Time-dependent, non-Newtonian behavior of viscoelastic
materials. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1486722980193887
Chicago Manual of Style (16th Edition):
Jackimiak, Paul Daniel. “Time-dependent, non-Newtonian behavior of viscoelastic
materials.” 1971. Doctoral Dissertation, The Ohio State University. Accessed March 04, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1486722980193887.
MLA Handbook (7th Edition):
Jackimiak, Paul Daniel. “Time-dependent, non-Newtonian behavior of viscoelastic
materials.” 1971. Web. 04 Mar 2021.
Vancouver:
Jackimiak PD. Time-dependent, non-Newtonian behavior of viscoelastic
materials. [Internet] [Doctoral dissertation]. The Ohio State University; 1971. [cited 2021 Mar 04].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486722980193887.
Council of Science Editors:
Jackimiak PD. Time-dependent, non-Newtonian behavior of viscoelastic
materials. [Doctoral Dissertation]. The Ohio State University; 1971. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1486722980193887
23.
Varischetti, Joshua Allen.
Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites.
Degree: 2012, University of Nevada – Reno
URL: http://hdl.handle.net/11714/3771
► In this research an investigation of the damping enhancement achieved, utilizing carbon nano fibers (CNF) to epoxy resin is presented along with a corresponding model…
(more)
▼ In this research an investigation of the damping enhancement achieved, utilizing carbon nano fibers (CNF) to epoxy resin is presented along with a corresponding model to predict damping performance. The addition of CNF fillers to the matrix allows for localized slip between the filler and the matrix on a nanoscale, wherein the matrix can de-bond from the CNFs, allowing the fillers to slip relative to the matrix; thereby, dissipating energy as frictional heat. Due to the nanoscale size of the filler, the specific surface area, of the CNF's, is very large when compared to traditional fiber reinforcement, this attribute allows small fractions of CNF fillers to have a large impact on the structural damping without any significant weight penalties. Moreover, once the composite returns to its undeformed configuration the interface between nano fillers and matrix will then re-establish the Van der Waals interactions that were broken to allow the slip. Thus, localized yet recoverable, frictional slip at the nano scale can be employed to significantly enhance strain dependent damping in composite structures wherein no permanent structural damage is evidenced. To better understand the damping response in CNF reinforced composites this study utilizes experimental and analytical approaches to develop modeling techniques that account for various fundamental attributes of high aspect ratio fillers, specifically the effect of filler aspect ratio, filler waviness, filler orientation relative to loading direction and the effect of multiple fillers on the damping performance and investigated in detail and corresponding modeling techniques are developed to address each of these factors in order to better predict the viscoelastic response of CNF reinforced composites. These models will be beneficial to address composite design while accounting for makeup, constituent properties, filler geometries, filler orientations, and their effective role in damping performance.
Advisors/Committee Members: Suhr, Jonghwan (advisor), Gibson, Ronald (committee member), Luo, Shen-yi (committee member), Shen, Yanto (committee member), Li, Qizhen (committee member).
Subjects/Keywords: Carbon Nano FIber; Damping; Viscoelasticity
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Varischetti, J. A. (2012). Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites. (Thesis). University of Nevada – Reno. Retrieved from http://hdl.handle.net/11714/3771
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):
Varischetti, Joshua Allen. “Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites.” 2012. Thesis, University of Nevada – Reno. Accessed March 04, 2021.
http://hdl.handle.net/11714/3771.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Varischetti, Joshua Allen. “Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites.” 2012. Web. 04 Mar 2021.
Vancouver:
Varischetti JA. Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites. [Internet] [Thesis]. University of Nevada – Reno; 2012. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/11714/3771.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Varischetti JA. Mechanical Damping Properties of Carbon Nanofiber Reinforced Composites. [Thesis]. University of Nevada – Reno; 2012. Available from: http://hdl.handle.net/11714/3771
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Ryerson University
24.
Bekuit, Jean-Jacques R. Boiluea.
A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams.
Degree: 2006, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A648
► Active-passive damping is getting more popular with designers because it combines the complementary passive and active features in the control of structural vibrations. The classical…
(more)
▼ Active-passive damping is getting more popular with designers because it combines the complementary passive and active features in the control of structural vibrations. The classical three-layer structure has a viscoelastic-layer sandwiched between the host beam and a piezoelectric-layer.The more prevalent assumptions for modeling the system are the use of Euler-Bernoulli beam theory for both the host beam and piezoelectric-layer, and Timoshenko beam theory for the viscoelastic-layer. The assumption that transverse displacement is constant through the thickness limits accuracy and applicability of the model. The current formulation expresses the through-the-thickness dependency of the field variables as polynomials while their span dependency across a finite element is cubically interpolated.The versatility of the formulation is demonstrated via static and dynamic studies of examples taken from the literature. A beam treated with active-passive damping is presented and examined. The constitutive relation of the viscoelastic layer is represented using fractional derivatives and the Grünwald approximation. The extended Hamilton's principle is used to derive the system governing equations which are integrated with the Newmark time-integration system.
Advisors/Committee Members: Oguamanam, Donatus (Thesis advisor).
Subjects/Keywords: Damping; Viscoelasticity; Mechanics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bekuit, J. R. B. (2006). A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A648
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):
Bekuit, Jean-Jacques R Boiluea. “A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams.” 2006. Thesis, Ryerson University. Accessed March 04, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A648.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bekuit, Jean-Jacques R Boiluea. “A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams.” 2006. Web. 04 Mar 2021.
Vancouver:
Bekuit JRB. A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams. [Internet] [Thesis]. Ryerson University; 2006. [cited 2021 Mar 04].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A648.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bekuit JRB. A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams. [Thesis]. Ryerson University; 2006. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A648
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
25.
Pavan, Théo Zeferino.
Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos.
Degree: PhD, Física Aplicada à Medicina e Biologia, 2011, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042011-163130/
;
► Mudanças nas características mecânicas de tecidos biológicos geralmente estão relacionadas com algum tipo de patologia. Técnicas de imagens elastográficas são métodos quantitativos de se estimar…
(more)
▼ Mudanças nas características mecânicas de tecidos biológicos geralmente estão relacionadas com algum tipo de patologia. Técnicas de imagens elastográficas são métodos quantitativos de se estimar as propriedades mecânicas de tecidos. Em geral, o objetivo destas técnicas de imagem é medir o movimento do tecido provocado por uma força interna ou externa. Por meio desse movimento, parâmetros viscoelásticos do meio em análise são reconstruídos. A força de excitação pode ser tanto quasi-estática, como dinâmica. O trabalho apresentado nesta tese aborda as técnicas de elastografia dinâmica e quasi-estática. Na abordagem quasi-estática, a elasticidade não-linear é estudada através de phantoms com características que simulam as do tecido humano. Na abordagem dinâmica, o movimento dinâmico promovido por força de radicação acústica é avaliado através de técnicas ultrassônicas e magnéticas. O desenvolvimento de materiais para serem usados como phantoms para elastografia por ultrassom é descrito. O comportamento elástico não-linear desses materiais foi analisado através de resultados de ensaios mecânicos. Esses materiais foram desenvolvidos para apresentarem uma relação tensão/deformação que não dependesse do módulo de cisalhamento para pequenas deformações, e foram projetados para serem usados em phantoms em que configurações heterogêneas são empregadas (por exemplo, phantoms com inclusões esféricas). O efeito da não-linearidade elástica dos materiais sobre o contraste, a relação sinal ruído e a relação contraste ruído de imagens elastográficas de um phantom contendo inclusões esféricas, sofrendo altas deformações (até 20%) foi investigada. Foi demonstrada a viabilidade de se medir movimentos vibratórios induzidos por feixes acústicos confocais através de um ultrassom Doppler que utiliza ondas contínuas. A interferência de feixes de ultrassom com pequena diferença de frequências provoca o aparecimento de uma força dinâmica no alvo. Foi demonstrada a formação de imagens de uma esfera rígida imersa em um phantom viscoelástico, através da varredura de ambos os transdutores (confocal e Doppler) pelo plano focal do transdutor confocal. O comportamento dinâmico de uma esfera magnetizada induzido por força de radicação acústica foi investigado. A esfera foi suspensa em água em configuração de pêndulo. Forcas estática de longa (poucos segundos) e curta (poucos milisegundos) duração foram utilizadas. O movimento da esfera foi medido através de um sensor magnetoresistivo. A partir da nova posição de equilíbrio em resposta à força de radicação de longa duração, a amplitude dessa força foi estimada. Para se estimar a viscosidade da água, o movimento de relaxação da esfera após a força ter sido desligada foi ajustado a um modelo de movimento-harmônico amortecido. O movimento de uma esfera rígida imersa em um phantom feito de gelatina, deslocada por força de radicação acústica, foi avaliado por meio de ecos ultrassônicas obtidos com um sistema pulso/eco. A teoria utilizada para se estimar os parâmetros viscoelásticos do phantom, usando o…
Advisors/Committee Members: Carneiro, Antonio Adilton Oliveira.
Subjects/Keywords: Elastografia; Elastography; Ultrasound; Ultrassom; Viscoelasticidade; Viscoelasticity
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APA (6th Edition):
Pavan, T. Z. (2011). Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042011-163130/ ;
Chicago Manual of Style (16th Edition):
Pavan, Théo Zeferino. “Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos.” 2011. Doctoral Dissertation, University of São Paulo. Accessed March 04, 2021.
http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042011-163130/ ;.
MLA Handbook (7th Edition):
Pavan, Théo Zeferino. “Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos.” 2011. Web. 04 Mar 2021.
Vancouver:
Pavan TZ. Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos. [Internet] [Doctoral dissertation]. University of São Paulo; 2011. [cited 2021 Mar 04].
Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042011-163130/ ;.
Council of Science Editors:
Pavan TZ. Estudos de técnicas ultrassônicas para análise de propriedades mecânicas de meios viscoelásticos. [Doctoral Dissertation]. University of São Paulo; 2011. Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042011-163130/ ;

University of Alberta
26.
Peng, Yanning.
A class of viscoelastic waves in rods and fluid filled
tubes.
Degree: MS, Department of Mathematics, 1991, University of Alberta
URL: https://era.library.ualberta.ca/files/3197xp146
Subjects/Keywords: Viscoelasticity – Mathematical models.
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Peng, Y. (1991). A class of viscoelastic waves in rods and fluid filled
tubes. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/3197xp146
Chicago Manual of Style (16th Edition):
Peng, Yanning. “A class of viscoelastic waves in rods and fluid filled
tubes.” 1991. Masters Thesis, University of Alberta. Accessed March 04, 2021.
https://era.library.ualberta.ca/files/3197xp146.
MLA Handbook (7th Edition):
Peng, Yanning. “A class of viscoelastic waves in rods and fluid filled
tubes.” 1991. Web. 04 Mar 2021.
Vancouver:
Peng Y. A class of viscoelastic waves in rods and fluid filled
tubes. [Internet] [Masters thesis]. University of Alberta; 1991. [cited 2021 Mar 04].
Available from: https://era.library.ualberta.ca/files/3197xp146.
Council of Science Editors:
Peng Y. A class of viscoelastic waves in rods and fluid filled
tubes. [Masters Thesis]. University of Alberta; 1991. Available from: https://era.library.ualberta.ca/files/3197xp146

University of Alberta
27.
Krebes, Edward S.
Seismic body waves in anelastic media.
Degree: PhD, Department of Physics, 1980, University of Alberta
URL: https://era.library.ualberta.ca/files/4q77ft54s
Subjects/Keywords: Seismic waves.; Viscoelasticity.
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Krebes, E. S. (1980). Seismic body waves in anelastic media. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/4q77ft54s
Chicago Manual of Style (16th Edition):
Krebes, Edward S. “Seismic body waves in anelastic media.” 1980. Doctoral Dissertation, University of Alberta. Accessed March 04, 2021.
https://era.library.ualberta.ca/files/4q77ft54s.
MLA Handbook (7th Edition):
Krebes, Edward S. “Seismic body waves in anelastic media.” 1980. Web. 04 Mar 2021.
Vancouver:
Krebes ES. Seismic body waves in anelastic media. [Internet] [Doctoral dissertation]. University of Alberta; 1980. [cited 2021 Mar 04].
Available from: https://era.library.ualberta.ca/files/4q77ft54s.
Council of Science Editors:
Krebes ES. Seismic body waves in anelastic media. [Doctoral Dissertation]. University of Alberta; 1980. Available from: https://era.library.ualberta.ca/files/4q77ft54s
28.
Στρατίκης, Νικόλαος.
Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων.
Degree: 2011, University of Patras
URL: http://nemertes.lis.upatras.gr/jspui/handle/10889/4561
► Στην παρούσα εργασία εκπονήθηκαν λεπτομερείς ατομιστικές προσομοιώσεις μοριακής δυναμικής (MD) στο ισοθερμοκρασιακό-ισοβαρές στατιστικό σύνολο (NPT), σε τήγματα κυκλικών μορίων πολυαιθυλενίου (PE), μοριακού μήκους από C6…
(more)
▼ Στην παρούσα εργασία εκπονήθηκαν λεπτομερείς ατομιστικές προσομοιώσεις μοριακής δυναμικής (MD) στο ισοθερμοκρασιακό-ισοβαρές στατιστικό σύνολο (NPT), σε τήγματα κυκλικών μορίων πολυαιθυλενίου (PE), μοριακού μήκους από C6 μέχρι C400. Οι προσομοιώσεις των συστημάτων από C6 μέχρι C16 έγιναν σε θερμοκρασία Τ=338 Κ και πίεση ίση με Ρ=1 atm, ενώ των συστημάτων από C24 μέχρι C400 σε θερμοκρασία Τ=450 Κ και πίεση Ρ=1 atm. Τα μικρά συστήματα, από C6 μέχρι C16, προσομοιώθηκαν σε διαφορετική θερμοκρασία από ότι τα υπόλοιπα συστήματα για να συγκριθούν με τα πειραματικά αποτελέσματα των von Meerwall et al. Αυστηρά μονοδιάσπαρτα και μη διαπλεγμένα δείγματα χρησιμοποιήθηκαν σε όλες τις περιπτώσεις. Παρουσιάζονται και συζητώνται λεπτομερέστατα τα αποτελέσματα των προσομοιώσεων για μια ποικιλία δομικών, θερμοδυναμικών και δομικών ιδιοτήτων των συγκεκριμένων συστημάτων, καθώς και η μεταβολή τους σε σχέση με το μήκος των αλυσίδων. Μεταξύ αυτών είναι η γυροσκοπική ακτίνα, η τοπική δυναμική, ο συντελεστής αυτοδιάχυσης του κέντρου μάζας των μορίων DG, ο μέγιστος χρόνος χαλάρωσης της αλυσίδας τd, το χαρακτηριστικό φάσμα των χρόνων χαλάρωσης της θεωρίας Rouse τp και ο δυναμικός δομικός παράγοντας S(q,t). Για τα συστήματα με μήκη στο εύρος από C24 μέχρι C400, τα αποτελέσματα συγκρίνονται με τα αντίστοιχα δεδομένα από προσομοιώσεις γραμμικών τηγμάτων πολυαιθυλενίου (ΡΕ) του ίδιου μήκους αλυσίδας (τα ανάλογα γραμμικά). Επίσης, εξαγάγαμε τη θεωρία Rouse για τα δακτυλιοειδή πολυμερή στην ολότητά της. Η θεωρία Rouse περιγράφει ικανοποιητικά τα αποτελέσματα των προσομοιώσεων των δακτυλιοειδών πολυμερικών τηγμάτων, ιδιαίτερα αυτών με μήκος αλυσίδας μεταξύ C50 και C170. Παρατηρώντας την εξάρτηση των DG, τp, ζ και η0 με το μήκος της αλυσίδας Ν, συμπεραίνουμε ότι τα δακτυλιοειδή τήγματα πολυαιθυλενίου (ΡΕ) υπακούουν περίπου τη δυναμική Rouse, ακόμα μέχρι και το μήκος αλυσίδας C400. Τούτο αποτελεί αξιοσημείωτο εύρημα, διότι το C400 είναι πάνω από δύο φορές μεγαλύτερο από το μήκος (~ C156) που χαρακτηρίζει τη μετάβαση από τη θεωρία Rouse στη θεωρία του ερπυσμού, όσον αφορά τα αντίστοιχα γραμμικά τήγματα πολυαιθυλενίου (ΡΕ). Ακόμα, υπολογίστηκαν δύο πολύ σημαντικές ρεολογικές ιδιότητες: το ιξώδες μηδενικού ρυθμού διάτμησης η0 και ο συντελεστής τριβής ζ. Σε συμφωνία με προγενέστερες θεωρητικές και πειραματικές μελέτες, τα αποτελέσματα των προσομοιώσεών μας υποστηρίζουν ότι η δομή των δακτυλιοειδών πολυμερικών τηγμάτων είναι περισσότερο συμπαγή σε σύγκριση με τα ανάλογα αντίστοιχα γραμμικά λόγω των μη ‘αλυσιδωτά συνδεδεμένων’ (nonconcatenated) διαμορφώσεών τους.
Δεν πρέπει να λησμονήσω να αναφέρω ότι τα αποτελέσματα που προέκυψαν από τις προσομοιώσεις των μικρών συστημάτων, από C6 μέχρι C16, συγκρίθηκαν με τα αντίστοιχα πειραματικά των von Meerwall et al. Παρατηρήθηκε μία μικρή απόκλιση, η οποία όμως είναι δικαιολογημένη.
–
Advisors/Committee Members: Μαυραντζάς, Βλάσιος, Stratikis, Nikolaos, Τσαμόπουλος, Ιωάννης, Στάικος, Γεώργιος.
Subjects/Keywords: Δακτυλιοειδή; Πολυμερή; Ιξωδοελαστικότητα; 668.42; Rings; Polymers; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Στρατίκης, . (2011). Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων. (Masters Thesis). University of Patras. Retrieved from http://nemertes.lis.upatras.gr/jspui/handle/10889/4561
Chicago Manual of Style (16th Edition):
Στρατίκης, Νικόλαος. “Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων.” 2011. Masters Thesis, University of Patras. Accessed March 04, 2021.
http://nemertes.lis.upatras.gr/jspui/handle/10889/4561.
MLA Handbook (7th Edition):
Στρατίκης, Νικόλαος. “Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων.” 2011. Web. 04 Mar 2021.
Vancouver:
Στρατίκης . Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων. [Internet] [Masters thesis]. University of Patras; 2011. [cited 2021 Mar 04].
Available from: http://nemertes.lis.upatras.gr/jspui/handle/10889/4561.
Council of Science Editors:
Στρατίκης . Υπολογιστική μελέτη της ιξωδοελαστικότητας τηγμάτων πολυμερικών δακτυλίων. [Masters Thesis]. University of Patras; 2011. Available from: http://nemertes.lis.upatras.gr/jspui/handle/10889/4561

Texas A&M University
29.
Srinivasa Parthasarathy, Atul.
A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility.
Degree: PhD, Civil Engineering, 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/149603
► The mechanical behavior of asphalt binders is nonlinear. The binders exhibit shear thinning/thickening behavior in steady shear tests and non-proportational behavior in other standard viscoelastic…
(more)
▼ The mechanical behavior of asphalt binders is nonlinear. The binders exhibit shear thinning/thickening behavior in steady shear tests and non-proportational behavior in other standard viscoelastic tests such as creep-recovery or stress relaxation tests. Moreover, they develop normal stress differences even in simple shear flows - a characteristic feature of nonlinear viscoelastic behavior.
Many researchers have asserted the importance of considering the nonlinearity of the mechanical behavior of asphalt binders for accurately estimating their performance under field conditions, and for comparing and ranking them accordingly. In order to do so, it is necessary to have a robust and reliable nonlinear viscoelastic model. However, most of the models available in the literature do not capture the various features of the nonlinear response of asphalt binders accurately. Those that could are too complicated and still possess other shortcomings.
Considering these issues, a new nonlinear viscoelastic model is developed here using a new Gibbs-potential based thermodynamic framework. The model is then corraborated with data from experiments in which the shear-thinning behavior and the nonproportional creep-recovery behavior were observed together. Finally, the model is used to evaluate the various criteria available for predicting rutting susceptibility of asphalt binders.
Results of the analysis of the rutting prediction criteria show that each criterion characterizes the resistance to permanent strain shown by asphalt binders over a different range of applied stress - the zero-shear viscosity at very low stress levels, the Superpave criterion at very high stress levels and the MSCR test in the intermediate range of stresses.
Advisors/Committee Members: Little, Dallas N (advisor), Rajagopal, Kumbakonam R (advisor), Epps Martin, Amy (committee member), Walton, Jay R (committee member).
Subjects/Keywords: Viscoelasticity; Consitutive modeling; Gibbs-potential; Rutting
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Srinivasa Parthasarathy, A. (2013). A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/149603
Chicago Manual of Style (16th Edition):
Srinivasa Parthasarathy, Atul. “A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility.” 2013. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021.
http://hdl.handle.net/1969.1/149603.
MLA Handbook (7th Edition):
Srinivasa Parthasarathy, Atul. “A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility.” 2013. Web. 04 Mar 2021.
Vancouver:
Srinivasa Parthasarathy A. A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Mar 04].
Available from: http://hdl.handle.net/1969.1/149603.
Council of Science Editors:
Srinivasa Parthasarathy A. A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/149603

Penn State University
30.
Ben Atitallah, Hassene.
Characterization and modeling of active fiber composites.
Degree: 2015, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/26546
► Active Fiber Composites (AFCs) are long fiber composites, where the fibers are made from lead zirconate titanate (PZT), which is one of the most widely…
(more)
▼ Active Fiber Composites (AFCs) are long fiber composites, where the fibers are made from lead zirconate titanate (PZT), which is one of the most widely used piezoelectric materials owing to its high electro-mechanical coupling and high piezoelectric coefficients. The PZT fibers are embedded in an epoxy matrix to give the composite more flexibility and more ruggedness. AFC utilizes interdigitated electrodes (IDE) along the direction of the fibers resulting in a d33-mode actuation (actuation parallel to the poling direction), which is advantageous since the d33 coefficient is almost twice the value of the d31 coefficient (actuation perpendicular to the poling direction). The development of AFCs offers a great potential for advancing structural health monitoring techniques and active vibration control and suppression thanks to their flexibility and lightweight, however AFCs piezoelectric performance is still not comparable to that of PZT transducers, where their effective actuation coefficient is 120 compared to 400x10-12 m/V for the bulk PZT. In addition, while in use, AFCs could be subjected to simultaneous mechanical loading, extreme environments, and moderate to high electric fields, leading to nonlinear and inelastic behaviors, strong coupling between various physical properties, and complex failure mechanisms. Moreover, AFCs have more than 50% volume content of polymer; the viscoelastic effect of the polymer matrix on the overall response of AFC can be significant especially at elevated temperatures. The effects of time and temperature on the mechanical and electrical characterization of AFCs have not been studied. Modeling these phenomena for the AFCs is an important step in redesigning them and obtaining reliable properties. However, there is not an available model that takes into consideration combined physical phenomena like time-dependence and piezoelectric non-linearity. In addition many models assume uniform electric field or perfect contact between the fibers and the electrodes, which neglects the effects of any IDE geometry parameters and electrical property of the matrix.
The overall objective of this proposed dissertation is to use a combination of experimental and numerical approaches to examine the overall behavior of the AFC with the goals of 1) quantifying the impact of the constituent properties (polymer matrix and PZT fiber) on coupled response of AFCs, 2) conducting an exhaustive parametric study focused on design of AFCs, and 3) building a model which takes into consideration non-uniform electric field behavior, non-linear behavior and time-dependent properties.
Mechanical, electrical and electro-mechanical experimental characterization of AFC and its constituents at various temperatures and loading rates were carried out to bring to light the behavior of AFC, including the time and temperature dependence of some of its properties. Numerical parametric study on the design of the composites that takes into effect the IDE geometry and matrix dielectric constant and modulus is conducted. In…
Advisors/Committee Members: Zoubeida Ounaies, Dissertation Advisor/Co-Advisor, Zoubeida Ounaies, Committee Chair/Co-Chair, Clive A Randall, Committee Member, Mary I Frecker, Committee Member, Charles E Bakis, Committee Member.
Subjects/Keywords: Piezoelectricity; composites; Temperature dependence; AFC; Viscoelasticity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ben Atitallah, H. (2015). Characterization and modeling of active fiber composites. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/26546
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):
Ben Atitallah, Hassene. “Characterization and modeling of active fiber composites.” 2015. Thesis, Penn State University. Accessed March 04, 2021.
https://submit-etda.libraries.psu.edu/catalog/26546.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ben Atitallah, Hassene. “Characterization and modeling of active fiber composites.” 2015. Web. 04 Mar 2021.
Vancouver:
Ben Atitallah H. Characterization and modeling of active fiber composites. [Internet] [Thesis]. Penn State University; 2015. [cited 2021 Mar 04].
Available from: https://submit-etda.libraries.psu.edu/catalog/26546.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ben Atitallah H. Characterization and modeling of active fiber composites. [Thesis]. Penn State University; 2015. Available from: https://submit-etda.libraries.psu.edu/catalog/26546
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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