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University of Ottawa
1.
Hayles, Meika.
Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
.
Degree: 2018, University of Ottawa
URL: http://hdl.handle.net/10393/37801
► Recycled concrete aggregates (RCA) are an eco-sustainable alternative to traditional aggregates. The equivalent mortar volume method has been developed to design RCA concrete with comparable…
(more)
▼ Recycled concrete aggregates (RCA) are an eco-sustainable alternative to traditional aggregates. The equivalent mortar volume method has been developed to design RCA concrete with comparable mechanical and strength properties to natural aggregate concrete by accounting for the adhered mortar that distinguishes RCA from natural aggregates. This method also presents an opportunity to reduce the cement content of RCA concrete, increasing its cement efficiency. Modifications to mix design procedures were introduced to improve the fresh state properties of RCA concrete with a 19% cement reduction compared to the control mix. Beams cast with the RCA concrete had similar flexural capacity to corresponding control beams, however the shear strength varied as a function of RCA content in the concrete. Polished core samples taken from RCA members showed that crack development and aggregate interlock in RCA members is influenced by the aggregate properties and the spacing of coarse aggregates, indicating that knowing the compressive strength of RCA concrete is not the only parameter required for member design.
Subjects/Keywords: Concrete;
Sustainability;
Materials;
Cement;
Structures
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APA ·
Chicago ·
MLA ·
Vancouver ·
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APA (6th Edition):
Hayles, M. (2018). Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
. (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/37801
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):
Hayles, Meika. “Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
.” 2018. Thesis, University of Ottawa. Accessed March 01, 2021.
http://hdl.handle.net/10393/37801.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hayles, Meika. “Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
.” 2018. Web. 01 Mar 2021.
Vancouver:
Hayles M. Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
. [Internet] [Thesis]. University of Ottawa; 2018. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10393/37801.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hayles M. Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members
. [Thesis]. University of Ottawa; 2018. Available from: http://hdl.handle.net/10393/37801
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Embry-Riddle Aeronautical University
2.
Waelchli, Robert.
A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages.
Degree: MSin Mechanical Engineering, Mechanical Engineering, 2018, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/edt/391
► Small satellites have become increasingly popular over the past thirty years, particularly since the adoption of the common CubeSat architecture early this century. Because…
(more)
▼ Small satellites have become increasingly popular over the past thirty years, particularly since the adoption of the common CubeSat architecture early this century. Because of their restricted volume and electrical budgets however, there are practical limits to the missions that small satellites may adopt. One potential near-term solution to the problem of limited electrical power may be the adoption of larger, flexible solar arrays. However, spacecraft with flexible appendages have historically presented attitude control challenges relating to platform stability given the dynamic response of the flexible components to applied torques. These challenges may be particularly disruptive to a small spacecraft with low inertia. Previous studies have examined minimizing the dynamic motion of flexible appendages via shaping control of the external torquers (attitude actuators), and damping the dynamic responses in various schemes.
This thesis presents the possible design of a new damper for the small, flexible spacecraft model. The design takes advantage of a smart material known as a magnetorheological (MR) fluid that was initially created in the 1940s, but has been subject to renewed interest over the past 30 years. A numerical model of the damper system is described and test articles with representative properties are subjected to dynamic testing to inform the model behavior. Completed simulation results for a spacecraft slewing maneuver are presented along with suggestions for future research and future design iterations.
Subjects/Keywords: Space Vehicles; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Waelchli, R. (2018). A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/edt/391
Chicago Manual of Style (16th Edition):
Waelchli, Robert. “A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages.” 2018. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/edt/391.
MLA Handbook (7th Edition):
Waelchli, Robert. “A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages.” 2018. Web. 01 Mar 2021.
Vancouver:
Waelchli R. A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 2018. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/edt/391.
Council of Science Editors:
Waelchli R. A Novel Magnetorheological Fluid Damper for a Small Spacecraft with Flexible Appendages. [Masters Thesis]. Embry-Riddle Aeronautical University; 2018. Available from: https://commons.erau.edu/edt/391
3.
St-Pierre, Luc.
The quasi-static and dynamic responses of metallic sandwich structures.
Degree: PhD, 2012, University of Cambridge
URL: http://www.dspace.cam.ac.uk/handle/1810/243443https://www.repository.cam.ac.uk/bitstream/1810/243443/2/license.txt
;
https://www.repository.cam.ac.uk/bitstream/1810/243443/5/ls451_thesis_revised.pdf.txt
;
https://www.repository.cam.ac.uk/bitstream/1810/243443/3/ls451_thesis_revised.pdf.txt
;
https://www.repository.cam.ac.uk/bitstream/1810/243443/6/ls451_thesis_revised.pdf.jpg
► Lattice materials are used as the core of sandwich panels to construct light and strong structures. This thesis focuses on metallic sandwich structures and has…
(more)
▼ Lattice materials are used as the core of sandwich panels to construct light and strong structures. This thesis focuses on metallic sandwich structures and has two main objectives: (i) explore how a surface treatment can improve the strength of a lattice material and (ii) investigate the collapse response of two competing prismatic sandwich cores employed in ship hulls. First, the finite element method is used to examine the effect of carburisation and strain hardening upon the compressive response of a pyramidal lattice made from hollow tubes or solid struts. The carburisation surface treatment increases the yield strength of the material, but its effects on pyramidal lattices are not known. Here, it is demonstrated that carburisation increases the plastic buckling strength of the lattice and reduces the slenderness ratio at which the transition from plastic to elastic buckling occurs. The predictions also showed that strain hardening increases the compressive strength of stocky lattices with a slenderness ratio inferior to ten, but without affecting the collapse mode of the lattice. Second, the quasi-static three-point bending responses of simply supported and clamped sandwich beams with a corrugated core or a Y-frame core are compared via experiments and finite element simulations. The role of the face-sheets is assessed by considering beams with (i) front-and-back faces present and (ii) front face present, but back face absent. These two beam designs are used to represent single hull and double hull ship structures, and they are compared on an equal mass basis by doubling the thickness of the front face when the back face is absent. Beams with a corrugated core are found to be slightly stronger than those with a Y-frame core, and two collapse mechanisms are identified depending upon beam span. Short beams collapse by indentation and for this collapse mechanism, beams without a back face outperform those with front-and back faces present. In contrast, long beams fail by Brazier plastic buckling and for this collapse mechanism, the presence of a back face strengthens the beam. Third, drop weight tests with an impact velocity of 5 m/s are performed on simply supported and clamped sandwich beams with a corrugated core or a Y-frame core. These tests are conducted to mimic the response of a sandwich hull in a ship collision. The responses measured at 5 m/s are found to be slightly stronger than those measured quasi-statically. The measurements are in reasonable agreement with finite element predictions. In addition, the finite element method is used to investigate whether the collapse mechanism at 5 m/s is different from the one obtained quasi-statically. The predictions indicate that sandwich beams that collapse quasi-statically by indentation also fail by indentation at 5 m/s. In contrast, the simulations for beams that fail quasi-statically by Brazier plastic buckling show that they collapse by indentation at 5 m/s. Finally, the dynamic indentation response of sandwich panels with a corrugated core or a Y-frame core…
Subjects/Keywords: Sandwich structures; Lattice materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
St-Pierre, L. (2012). The quasi-static and dynamic responses of metallic sandwich structures. (Doctoral Dissertation). University of Cambridge. Retrieved from http://www.dspace.cam.ac.uk/handle/1810/243443https://www.repository.cam.ac.uk/bitstream/1810/243443/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/5/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/3/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/6/ls451_thesis_revised.pdf.jpg
Chicago Manual of Style (16th Edition):
St-Pierre, Luc. “The quasi-static and dynamic responses of metallic sandwich structures.” 2012. Doctoral Dissertation, University of Cambridge. Accessed March 01, 2021.
http://www.dspace.cam.ac.uk/handle/1810/243443https://www.repository.cam.ac.uk/bitstream/1810/243443/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/5/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/3/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/6/ls451_thesis_revised.pdf.jpg.
MLA Handbook (7th Edition):
St-Pierre, Luc. “The quasi-static and dynamic responses of metallic sandwich structures.” 2012. Web. 01 Mar 2021.
Vancouver:
St-Pierre L. The quasi-static and dynamic responses of metallic sandwich structures. [Internet] [Doctoral dissertation]. University of Cambridge; 2012. [cited 2021 Mar 01].
Available from: http://www.dspace.cam.ac.uk/handle/1810/243443https://www.repository.cam.ac.uk/bitstream/1810/243443/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/5/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/3/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/6/ls451_thesis_revised.pdf.jpg.
Council of Science Editors:
St-Pierre L. The quasi-static and dynamic responses of metallic sandwich structures. [Doctoral Dissertation]. University of Cambridge; 2012. Available from: http://www.dspace.cam.ac.uk/handle/1810/243443https://www.repository.cam.ac.uk/bitstream/1810/243443/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/5/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/3/ls451_thesis_revised.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/243443/6/ls451_thesis_revised.pdf.jpg

University of Cambridge
4.
St-Pierre, Luc.
The quasi-static and dynamic responses of metallic sandwich structures.
Degree: PhD, 2012, University of Cambridge
URL: https://doi.org/10.17863/CAM.14021
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553217
► Lattice materials are used as the core of sandwich panels to construct light and strong structures. This thesis focuses on metallic sandwich structures and has…
(more)
▼ Lattice materials are used as the core of sandwich panels to construct light and strong structures. This thesis focuses on metallic sandwich structures and has two main objectives: (i) explore how a surface treatment can improve the strength of a lattice material and (ii) investigate the collapse response of two competing prismatic sandwich cores employed in ship hulls. First, the finite element method is used to examine the effect of carburisation and strain hardening upon the compressive response of a pyramidal lattice made from hollow tubes or solid struts. The carburisation surface treatment increases the yield strength of the material, but its effects on pyramidal lattices are not known. Here, it is demonstrated that carburisation increases the plastic buckling strength of the lattice and reduces the slenderness ratio at which the transition from plastic to elastic buckling occurs. The predictions also showed that strain hardening increases the compressive strength of stocky lattices with a slenderness ratio inferior to ten, but without affecting the collapse mode of the lattice. Second, the quasi-static three-point bending responses of simply supported and clamped sandwich beams with a corrugated core or a Y-frame core are compared via experiments and finite element simulations. The role of the face-sheets is assessed by considering beams with (i) front-and-back faces present and (ii) front face present, but back face absent. These two beam designs are used to represent single hull and double hull ship structures, and they are compared on an equal mass basis by doubling the thickness of the front face when the back face is absent. Beams with a corrugated core are found to be slightly stronger than those with a Y-frame core, and two collapse mechanisms are identified depending upon beam span. Short beams collapse by indentation and for this collapse mechanism, beams without a back face outperform those with front-and back faces present. In contrast, longbeams fail by Brazier plastic buckling and for this collapse mechanism, the presence of a back face strengthens the beam. Third, drop weight tests with an impact velocity of 5 m/s are performed on simply supported and clamped sandwich beams with a corrugated core or a Y-frame core. These tests are conducted to mimic the response of a sandwich hull in a ship collision. The responses measured at 5 m/s are found to be slightly stronger than those measured quasi-statically. The measurements are in reasonable agreement with finite element predictions. In addition, the finite element method is used to investigate whether the collapse mechanism at 5 m/s is different from the one obtained quasi-statically. The predictions indicate that sandwich beams that collapse quasi-statically by indentation also fail by indentation at 5 m/s. In contrast, the simulations for beams that fail quasi-statically by Brazier plastic buckling show that they collapse by indentation at 5 m/s. Finally, the dynamic indentation response of sandwich panels with a corrugated core or a Y-frame core…
Subjects/Keywords: 620; Sandwich structures; Lattice materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
St-Pierre, L. (2012). The quasi-static and dynamic responses of metallic sandwich structures. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.14021 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553217
Chicago Manual of Style (16th Edition):
St-Pierre, Luc. “The quasi-static and dynamic responses of metallic sandwich structures.” 2012. Doctoral Dissertation, University of Cambridge. Accessed March 01, 2021.
https://doi.org/10.17863/CAM.14021 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553217.
MLA Handbook (7th Edition):
St-Pierre, Luc. “The quasi-static and dynamic responses of metallic sandwich structures.” 2012. Web. 01 Mar 2021.
Vancouver:
St-Pierre L. The quasi-static and dynamic responses of metallic sandwich structures. [Internet] [Doctoral dissertation]. University of Cambridge; 2012. [cited 2021 Mar 01].
Available from: https://doi.org/10.17863/CAM.14021 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553217.
Council of Science Editors:
St-Pierre L. The quasi-static and dynamic responses of metallic sandwich structures. [Doctoral Dissertation]. University of Cambridge; 2012. Available from: https://doi.org/10.17863/CAM.14021 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553217

University of Oklahoma
5.
Drury, Jonathan.
Shear Performance of Non-Traditional Concrete.
Degree: PhD, 2018, University of Oklahoma
URL: http://hdl.handle.net/11244/301339
► Concrete is the second most consumed material in the world, second only to water. Concrete has been around in different forms for centuries, and science…
(more)
▼ Concrete is the second most consumed material in the world, second only to water. Concrete has been around in different forms for centuries, and science and technology continually push the previously believed limits. Two such types of concrete are self-consolidating concrete (SCC) and cement-limiting concrete. While each is vastly different from the other, they present similar problems to designers and engineers. Practitioners have implemented new technologies such as fiber reinforcement to combat issues with these concretes, but the overall behavior and internal mechanism of these concretes are not thoroughly understood. This study investigated the shear behavior of seven different concrete types: conventional concrete with micro-fibers, conventional concrete with micro-fibers and macro-fibers, cement-limiting concrete, cement-limiting concrete with micro-fibers, cement-limiting concrete with micro-fibers and macro-fibers, SCC, SCC with macro-fibers, and compared their behavior to the behavior of conventional concrete. Additionally, a newly proposed push-off test method was developed, investigated, and compared to historic methods.
The experimental programs consisted of 15 full-scale shear beams without shear reinforcement in the test regions (3 with conventional concrete, 6 with cement-limiting concrete, and 6 with SCC), 24 push-off specimens (3 for each of the eight concrete mixtures investigated), and many small-scale specimens to capture the fresh and hardened properties of the concrete mixtures. The shear beams were tested under a simply supported four-point loading condition.
Results of this study showed that fiber reinforced concrete has more variable performance, but that fiber reinforcement can mitigate the negative performance aspects of SCC and cement-limiting concrete. It was shown that micro-fibers amplified the cohesion performance of existing concrete matrixes, but that macro-fiber tend to govern the performance of a concrete mixture. It was shown than that the optimized gradation of the cement-limiting concrete provided the highest aggregate interlock, but that aggregate interlock is not the best predictor of shear transfer performance between two concrete surfaces. Lastly, this study showed that the proposed push-off test is not only an acceptable method for analyzing aggregate interlock, but it is an improvement due to the ability to obtain more data from it, improved quality control, simplified analysis, and repeatability of the outcomes.
Advisors/Committee Members: Volz, Jeffery (advisor), Floyd, Royce (committee member), Harvey, P. Scott (committee member), Ramseyer, Christopher (committee member), Shadravan, Shideh (committee member).
Subjects/Keywords: Civil Engineering Materials Structures
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Drury, J. (2018). Shear Performance of Non-Traditional Concrete. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/301339
Chicago Manual of Style (16th Edition):
Drury, Jonathan. “Shear Performance of Non-Traditional Concrete.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed March 01, 2021.
http://hdl.handle.net/11244/301339.
MLA Handbook (7th Edition):
Drury, Jonathan. “Shear Performance of Non-Traditional Concrete.” 2018. Web. 01 Mar 2021.
Vancouver:
Drury J. Shear Performance of Non-Traditional Concrete. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/11244/301339.
Council of Science Editors:
Drury J. Shear Performance of Non-Traditional Concrete. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/301339

Michigan Technological University
6.
Shen, Michael.
MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING.
Degree: PhD, Department of Mechanical Engineering-Engineering Mechanics, 2017, Michigan Technological University
URL: https://digitalcommons.mtu.edu/etdr/465
► Armored Vehicle Launched Bridge (AVLB) has been analyzed on its load carrying capacity and stability of bracing with theoretical computation, FEA simulation and full-size…
(more)
▼ Armored Vehicle Launched Bridge (AVLB) has been analyzed on its load carrying capacity and stability of bracing with theoretical computation, FEA simulation and full-size bridge engineering testing. A new method has been developed out to calculate bending loads used to define and validate required lateral and torsional brace stiffness and strength in beam structure.
In the analyses of strength, stability and testing, the AVLB Military Load Class (MLC) 70 Bridge endured 2500 MLC 85T crossings working load without showing signs of damage or over stressed. It is recommended that the AVLB MLC 70 documentation and signage be updated to MLC 85T (Track) rating for newly converted or overhauled MLC 70 Bridge. Testing of the fatigued bridge could be continued the analysis to develop an inspection and service life indicator, such as Health Monitoring System, to help the sustainment and field maintenance at U.S. Army and U.S. Marines Corps (USMC).
Advisors/Committee Members: Gregory M. Odegard.
Subjects/Keywords: structures; Aerospace Engineering; Automotive Engineering; Structures and Materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shen, M. (2017). MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING. (Doctoral Dissertation). Michigan Technological University. Retrieved from https://digitalcommons.mtu.edu/etdr/465
Chicago Manual of Style (16th Edition):
Shen, Michael. “MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING.” 2017. Doctoral Dissertation, Michigan Technological University. Accessed March 01, 2021.
https://digitalcommons.mtu.edu/etdr/465.
MLA Handbook (7th Edition):
Shen, Michael. “MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING.” 2017. Web. 01 Mar 2021.
Vancouver:
Shen M. MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING. [Internet] [Doctoral dissertation]. Michigan Technological University; 2017. [cited 2021 Mar 01].
Available from: https://digitalcommons.mtu.edu/etdr/465.
Council of Science Editors:
Shen M. MILITARY ASSAULT BRIDGING STRUCTURAL ANALYSIS AND LOAD TESTING. [Doctoral Dissertation]. Michigan Technological University; 2017. Available from: https://digitalcommons.mtu.edu/etdr/465

University of Illinois – Urbana-Champaign
7.
Choi, Jonghyun.
Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors.
Degree: PhD, Mechanical Engineering, 2018, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/101352
► Nanomaterials have been extensively investigated by the research community owing to their extraordinary properties and functionalities that significantly surpass their bulk counterparts. Among a variety…
(more)
▼ Nanomaterials have been extensively investigated by the research community owing to their extraordinary properties and functionalities that significantly surpass their bulk counterparts. Among a variety of nanomaterials, two dimensional (2D) nanomaterials, represented by graphene and transition metal dichalcogenides (TMDCs), have captivated academic and industrial attentions because of their promise in future electronics, surface coating, biosensing, as well as the compatibility with the scalable and low-cost, top-down fabrication process. In this dissertation, I further explore the potentiality of 2D
materials as an advanced surface and field-effect transistor (FET)-based biochemical sensing platform, and investigate electrical double layer (EDL) formation on 2D
materials.
First, I present various three-dimensional (3D) integration techniques of 2D
materials that exhibit promise as a biosensing platform, tunable wetting surface, and stretchable electronic device. I demonstrate that 2D
materials could be integrated with 3D microstructure substrates with a novel and simple substrate engineering technique that utilizes solvent-induced swelling of substrates. In addition, I report on developing flower-like
structures (i.e., nanoflowers) of molybdenum disulfide (MoS2) grown by metal-organic chemical vapor deposition (MOCVD), and further demonstrate dual-scale hierarchical
structures by introducing additional buckle-delamination induced microscale crumples using a shape-memory polymer. Moreover, I achieve bio-inspired hierarchical
structures of graphene by combined use of 3D microstructure substrates and mechanically-driven nanoscale crumples of graphene, which exhibit a potential for a highly sensitive biochemical sensor platform.
Second, I investigate graphene FETs for an advanced electrophysiological study, as well as for the understanding of EDL formation on atomically-thin
materials. I demonstrate simultaneous electrical recording of controlled and stimulated behaviors of optogenetically encoded skeletal muscle cells and neurons. The recorded electrical signals corresponded well with the stimulation patterns of optogenetically encoded cells, demonstrating the successful real-time and simultaneous sensing of extracellular action potentials from target cells based on graphene FETs. Furthermore, I study how the EDL, which is an essential component for top solution-gated FETs and biosensors, is affected by the surface properties of underlying substrates beneath graphene. Hydrophobic substrates are demonstrated to disrupt the EDL formation on graphene, which is evidenced by transconductance measurements by FETs, capacitance measurements by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), as well as molecular dynamics (MD) simulations.
This thesis represents significant advancements in assembly and integration of 2D
materials for diverse novel applications as well as fundamental scientific research. Our results offer unique strategies toward superlative surface coatings, stretchable electronics,…
Advisors/Committee Members: Nam, SungWoo (advisor), Nam, SungWoo (Committee Chair), Aluru, Narayana R (committee member), Li, Xiuling (committee member), Kim, Seok (committee member).
Subjects/Keywords: 2D materials; 3D structures; interfaces; sensors
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Choi, J. (2018). Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/101352
Chicago Manual of Style (16th Edition):
Choi, Jonghyun. “Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors.” 2018. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 01, 2021.
http://hdl.handle.net/2142/101352.
MLA Handbook (7th Edition):
Choi, Jonghyun. “Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors.” 2018. Web. 01 Mar 2021.
Vancouver:
Choi J. Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2018. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/2142/101352.
Council of Science Editors:
Choi J. Assembly and integration of two-dimensional nanomaterials for advanced interfaces and sensors. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2018. Available from: http://hdl.handle.net/2142/101352

Hong Kong University of Science and Technology
8.
Yang, Meng.
Bacterial behavior on honeycomb patterned surfaces.
Degree: 2013, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-62656
;
https://doi.org/10.14711/thesis-b1255095
;
http://repository.ust.hk/ir/bitstream/1783.1-62656/1/th_redirect.html
► The adhesion of bacteria to medical implants forming biofilms might lead to healthcare-associated infections. Initial bacterial adhesion is mediated by material surface properties. Therefore, control…
(more)
▼ The adhesion of bacteria to medical implants forming biofilms might lead to healthcare-associated infections. Initial bacterial adhesion is mediated by material surface properties. Therefore, control of bacterial adhesion to material surfaces is important for reducing infection. Numerous researches have been devoted to the chemical and physical modification of biomaterial surfaces to control initial bacterial adhesion. However, the successful design of biomaterials for the treatment of infections remains a challenge. Surface topographic patterns of micro- or nano-scale have been effective to manipulate behavior of different types of cells. Previously, the bacterial behavior on the micro-pillar patterned surfaces has been studied in our group and confirmed that the micro-pillar pattern do have effects on the bacterial behavior. Now in this study we further fabricated a honeycomb pattern which provided a reduced continuous surface area compared with micro-pillar pattern. The honeycomb patterns on silicon substrate with characteristic dimensions varied from 0.5 μm to 10 μm were fabricated. Two typical bacteria with distinctive shapes (E.coli and S.aureus) were used as study models. After culturing the samples with bacteria, the effects of honeycomb patterns on the bacterial adhesion, growth, proliferation and viability were investigated. Experimental results show that the honeycomb topography with specific feature size around 1 μm can significantly reduce bacterial adhesion. Furthermore, the honeycomb patterns can inhibit bacterial growth and change the direction of growth when the bacterial is confined into a well. These influences may result from the physical confinement effect on bacteria. By comparing Sample_UP vs. Sample_DOWN, the adherent bacterial is much less on Sample_DOWN, but the trends of bacterial adhesion are the same and irrespective of the gravity of bacteria. In comparison with bacterial responses to pillar patterns, we found that topographic patterns with dimensions approaching to bacterial size can provide stronger physical confinement effect than others. However, the viability of the bacteria does not obviously influenced by the pillar and honeycomb topography within 24h. This study is expected to contribute to better understanding of topographic effects on bacterial behavior and healthcare-associated infections on biomaterials.
Subjects/Keywords: Bacteria
; Adhesion
; Biomedical materials
; Surfaces
; Honeycomb structures
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APA ·
Chicago ·
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CSE |
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APA (6th Edition):
Yang, M. (2013). Bacterial behavior on honeycomb patterned surfaces. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-62656 ; https://doi.org/10.14711/thesis-b1255095 ; http://repository.ust.hk/ir/bitstream/1783.1-62656/1/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):
Yang, Meng. “Bacterial behavior on honeycomb patterned surfaces.” 2013. Thesis, Hong Kong University of Science and Technology. Accessed March 01, 2021.
http://repository.ust.hk/ir/Record/1783.1-62656 ; https://doi.org/10.14711/thesis-b1255095 ; http://repository.ust.hk/ir/bitstream/1783.1-62656/1/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):
Yang, Meng. “Bacterial behavior on honeycomb patterned surfaces.” 2013. Web. 01 Mar 2021.
Vancouver:
Yang M. Bacterial behavior on honeycomb patterned surfaces. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2013. [cited 2021 Mar 01].
Available from: http://repository.ust.hk/ir/Record/1783.1-62656 ; https://doi.org/10.14711/thesis-b1255095 ; http://repository.ust.hk/ir/bitstream/1783.1-62656/1/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:
Yang M. Bacterial behavior on honeycomb patterned surfaces. [Thesis]. Hong Kong University of Science and Technology; 2013. Available from: http://repository.ust.hk/ir/Record/1783.1-62656 ; https://doi.org/10.14711/thesis-b1255095 ; http://repository.ust.hk/ir/bitstream/1783.1-62656/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Delft University of Technology
9.
Wink, H.P. (author).
Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's).
Degree: 2015, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:b9218b73-ccd5-4cbc-b9d7-326440817b3b
► Existing structures are built according to the valid codes at that time and reaching their design life time. The traffic loads and traffic intensity has…
(more)
▼ Existing
structures are built according to the valid codes at that time and reaching their design life time. The traffic loads and traffic intensity has also increased. In addition, the existing reinforced concrete
structures are exposed to degradation mechanisms, like chlorides and carbonation during their lifetime. Existing concrete road infrastructure can have the need to restore the structural performance or the durability. Advanced Ce-mentitious
Materials (ACM’s) has the potential for retrofitting due to the increased strength properties and durability. High Performance Concrete (HPC) and especially Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) have increased strength properties and a dense matrix, which prevents the ingress of detrimental substances. Strain Hardening Cementitious Composites (SHCC) has a high tensile strain capacity, whereby the crack widths are limited. The strengthening effect of SHCC retrofitting is negligible. The biggest potential for retrofitting of existing infrastructure with ACM’s is in retrofitting of durability problems. The structural shear strength problems are less severe than originally thought and traditional structural retrofit solutions like FRP lamellas and external prestressing seems to be more feasible and more economic solutions compared to an ACM layer retrofit system. On the other hand, the reinforcement corrosion of concrete
structures is expected to increase. Moreover, HPC and UHPFRC both have a dense matrix to prevent the ingress of detrimental substances. SHCC exhibits a large tensile strain capacity and limited crack widths. A specific durability ACM retrofit solution is used in a numerical model (see Figure 1). The durability retrofitting is based on a cast in situ ACM layer on a vertical existing surface, where the time-dependent development of the ACM properties and the interface between the ACM layer and old concrete determine the structural behav-iour. The mechanical properties develop due to the on-going hydration. Shrinkage is the cause of the main stresses in the model and the stresses are partly relaxed by the tensile creep behaviour of the ACM layer. The basic failure modes are debonding of the ACM layer at the free ends and transverse cracking in the ACM layer. A vertical existing surface is used, because vertical surfaces of road infrastructure
structures can exhibit dura-bility problems due to de-icing salts in splash water and also tidal zones of marine
structures. A parameter study is performed to enhance the understanding of the structural behaviour due to the time-dependent behaviour of the new ACM layer. A thicker ACM layer causes more debonding and transverse crack-ing behaviour, because the total shrinkage displacement is higher which causes higher stresses. A larger shrink-age strain causes higher stresses and more cracking. The creep in the ACM layer causes a stress relaxation. Increased creep compliance results in less severe cracking. The influence of the thickness of the old concrete structure and the length of the ACM…
Advisors/Committee Members: Hordijk, D.A. (mentor), Reitsema, A.D. (mentor), Savija, B. (mentor), Grünewald, S. (mentor), Houben, L. (mentor).
Subjects/Keywords: retrofitting; existing structures; Advanced Cementitious Materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
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APA (6th Edition):
Wink, H. P. (. (2015). Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's). (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:b9218b73-ccd5-4cbc-b9d7-326440817b3b
Chicago Manual of Style (16th Edition):
Wink, H P (author). “Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's).” 2015. Masters Thesis, Delft University of Technology. Accessed March 01, 2021.
http://resolver.tudelft.nl/uuid:b9218b73-ccd5-4cbc-b9d7-326440817b3b.
MLA Handbook (7th Edition):
Wink, H P (author). “Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's).” 2015. Web. 01 Mar 2021.
Vancouver:
Wink HP(. Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's). [Internet] [Masters thesis]. Delft University of Technology; 2015. [cited 2021 Mar 01].
Available from: http://resolver.tudelft.nl/uuid:b9218b73-ccd5-4cbc-b9d7-326440817b3b.
Council of Science Editors:
Wink HP(. Retrofitting of Existing Infrastructure Structures with Advanced Cementitious Materials (ACM's). [Masters Thesis]. Delft University of Technology; 2015. Available from: http://resolver.tudelft.nl/uuid:b9218b73-ccd5-4cbc-b9d7-326440817b3b

Florida Atlantic University
10.
Tauhiduzzaman, Mohammad.
FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS.
Degree: 2019, Florida Atlantic University
URL: http://fau.digital.flvc.org/islandora/object/fau:42217
► The objective of the research presented in this thesis is to develop analysis and test procedures for the characterization of disbonding crack growth in a…
(more)
▼ The objective of the research presented in this thesis is to develop analysis and test procedures for the characterization of disbonding crack growth in a honeycomb (HC) core sandwich structure. Face sheet-to-core disbonding are of particular interest to aircraft certification authorities due to several in-service occurrences. Experimental investigation was initially focused on the mode I dominated Single Cantilever Beam (SCB) test method. Various data reduction methodologies were employed to determine the fracture toughness. The MBT method produced the most consistent and conservative results. Finite element analysis (FEA) a double periodic array of hexagonal cells was conducted to determine the effective in-plane extensional modulus and Poisson ratio of the HC core. It was shown that deformation constraints on the core, due to attachment of the core to rigid face sheets, will drastically change the behavior of the HC core. The response changes from being governed by bending to stretching which substantially elevates the effective in-plane modulus. Fracture mechanics analysis of a face/core interface crack in a HC core SCB specimen was performed using FEA. The influence of in-plane properties of the constrained core on energy release rate and mode mixity phase angle was examined. Use of plane strain conditions and an elevated modulus of the constrained core in the analysis is recommended. The approach is substantiated by testing of HC core SCB sandwich. Test results showed good agreement with FEA prediction of compliance and kink angle.
2019
Degree granted: Dissertation (Ph.D.) – Florida Atlantic University, 2019.
Collection: FAU
Advisors/Committee Members: Carlsson, Leif A. (Thesis advisor), Florida Atlantic University (Degree grantor), Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science.
Subjects/Keywords: Honeycomb structures; Fracture mechanics; Strength of materials; Airframes – Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Tauhiduzzaman, M. (2019). FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS. (Thesis). Florida Atlantic University. Retrieved from http://fau.digital.flvc.org/islandora/object/fau:42217
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):
Tauhiduzzaman, Mohammad. “FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS.” 2019. Thesis, Florida Atlantic University. Accessed March 01, 2021.
http://fau.digital.flvc.org/islandora/object/fau:42217.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Tauhiduzzaman, Mohammad. “FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS.” 2019. Web. 01 Mar 2021.
Vancouver:
Tauhiduzzaman M. FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS. [Internet] [Thesis]. Florida Atlantic University; 2019. [cited 2021 Mar 01].
Available from: http://fau.digital.flvc.org/islandora/object/fau:42217.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Tauhiduzzaman M. FACE/CORE DISBONDING FRACTURE OF HONEYCOMB CORE SANDWICH PANELS. [Thesis]. Florida Atlantic University; 2019. Available from: http://fau.digital.flvc.org/islandora/object/fau:42217
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Clemson University
11.
Schultz, Jesse.
Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures.
Degree: MS, Mechanical Engineering, 2011, Clemson University
URL: https://tigerprints.clemson.edu/all_theses/1106
► The effective static mechanical properties, such as the moduli of elasticity and rigidity and Poisson's ratio, of honeycomb cellular meso-structures are capable of control due…
(more)
▼ The effective static mechanical properties, such as the moduli of elasticity and rigidity and Poisson's ratio, of honeycomb cellular meso-
structures are capable of control due to variations of their cellular geometry. While the dynamic properties of these
structures are a popular topic of research, there is a lack of both consistent modeling methods and generalizations in terms of honeycomb cellular geometry. In order to fill these gaps, this study presents a standard set of methods for the finite element analysis (FEA) of honeycomb cellular
materials subject to dynamic loading conditions, as well as illustrates the effects of the cellular geometry parameters on a honeycomb structure's response to non-static loads. The first study performed compares the response of four different hexagonal honeycomb geometries to in-plane impact of varying velocities, which show different failure modes while maintaining a constant effective modulus in the loading direction. The second section describes a newly developed design of experiments method for the simulation of honeycomb cellular
materials that can efficiently gather sufficient data for the generalization of the relationships between cellular geometry and energy absorbed by the structure due to plastic deformation of the cells. This allows for the targeting of specific responses through the modification of cellular geometric parameters. The final study discussed in this thesis discusses the simulation of models of reduced size in order to decrease the computational expense of the finite element analyses, while measuring error when compared to
structures of larger numbers of cells. This allows an analyst to determine the desired trade-off between time required to perform an analysis and accuracy of the results.
Advisors/Committee Members: Summers, Joshua D, Thompson , Lonny L, Joseph , Paul F, Ju , Jaehyung.
Subjects/Keywords: Cellular Materials; FEA; Honeycomb; Impact; Meso-structures; Meta-Materials; Mechanical Engineering
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Schultz, J. (2011). Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1106
Chicago Manual of Style (16th Edition):
Schultz, Jesse. “Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures.” 2011. Masters Thesis, Clemson University. Accessed March 01, 2021.
https://tigerprints.clemson.edu/all_theses/1106.
MLA Handbook (7th Edition):
Schultz, Jesse. “Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures.” 2011. Web. 01 Mar 2021.
Vancouver:
Schultz J. Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Mar 01].
Available from: https://tigerprints.clemson.edu/all_theses/1106.
Council of Science Editors:
Schultz J. Modeling and Finite Element Analysis Methods for the Dynamic Crushing of Honeycomb Cellular Meso-Structures. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1106

Rice University
12.
Gong, Yongji.
2D Materials in Lego Style: Synthesis, Characterizations and Applications.
Degree: PhD, Natural Sciences, 2015, Rice University
URL: http://hdl.handle.net/1911/87824
► Recently, the emergence and development of 2D materials with various optical and electrical properties has opened up new routes for electronic and optoelectronic device fabrication…
(more)
▼ Recently, the emergence and development of 2D
materials with various optical and electrical properties has opened up new routes for electronic and optoelectronic device fabrication based on atomically thin layers. For example, graphene behaves as a semi-metal with extremely high mobility, hexagonal boron nitride (h-BN) is a good insulator and monolayer TMDs such as MoS2, MoSe2 and WSe2 are semiconductors with direct band gap. This diversity offers the opportunity to construct atomically thin electronics based entirely on 2D
materials. One of the most promising applications is to get 2D integrated circuits to replace the traditional silicon based ones, which will be much thinner and faster.
2D
materials can be considered to be analogous to Lego blocks. The Lego game is to use different Lego blocks to get a complicated Lego building. Similarly, we can use different 2D
materials to get the corresponding integrated circuits or devices for energy related applications. Based on this purpose, we need different 2D blocks, which are the most fundamental parts in the 2D world, 2D
materials with tunable properties, and different strategies to combine the 2D
materials together.
Chapter 1 focuses on synthesis, characterization and applications of pristine 2D
materials, which are the fundamental blocks for the 2D world. In this part, we synthesized different 2D
materials such as insulator (h-BN), metal (graphene) and semiconductors (MX2, M = metal and X = chalcogen) for different applications. There are two directions in this part: one is to explore new 2D
materials and the other one is to improve the growth of 2D
materials to push them closer to their real applications. Moreover, semiconductors with different band gap (from 1.1 eV to 2.8 eV) and different type (p type and n type) have been developed. Furthermore, we improved the growth of different 2D
materials to get their millimeter-scale single crystals or even continuous film.
In the coming Chapter 2, we focused on the 2D alloys. The purpose of alloying 2D
materials is to engineer the phase and band gap by changing the composition in the alloys. By this, we can tune the optical and electrical properties in 2D
materials very easily. The first project in this part is about h-BNC system, which can open a band gap in graphene system, resulting in both high mobilities and high ON-OFF ratio in their transistors. Then we developed the MoS2-xSex (x, 0-2) alloys, in which the band gap can be continuously tuned from 1.50 eV to 1.84 eV. At last, RexMo1-xS2 (x, 0-1) system is developed to study the phase transition with different x.
In Chapter 3, heterostructures based on different 2D
materials are developed by different strategies. For example, we can get h-BN/h-BNC/graphene lateral heterostructure by combing a conversion method and lithography. We also developed the heterostructures based on MoS2/WS2 and MoSe2/WSe2 by a one-step growth method and two-step growth method, respectively. In both of them, we can get the in-plane and vertical heterostructures. The interface of the in-plane…
Advisors/Committee Members: Ajayan, Pulickel M. (advisor), Jun, Lou (committee member), Marti, Angel (committee member).
Subjects/Keywords: 2D materials; pristine 2D materials; alloying 2D materials; 2D heterostructures; 3D structures; energy
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gong, Y. (2015). 2D Materials in Lego Style: Synthesis, Characterizations and Applications. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/87824
Chicago Manual of Style (16th Edition):
Gong, Yongji. “2D Materials in Lego Style: Synthesis, Characterizations and Applications.” 2015. Doctoral Dissertation, Rice University. Accessed March 01, 2021.
http://hdl.handle.net/1911/87824.
MLA Handbook (7th Edition):
Gong, Yongji. “2D Materials in Lego Style: Synthesis, Characterizations and Applications.” 2015. Web. 01 Mar 2021.
Vancouver:
Gong Y. 2D Materials in Lego Style: Synthesis, Characterizations and Applications. [Internet] [Doctoral dissertation]. Rice University; 2015. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1911/87824.
Council of Science Editors:
Gong Y. 2D Materials in Lego Style: Synthesis, Characterizations and Applications. [Doctoral Dissertation]. Rice University; 2015. Available from: http://hdl.handle.net/1911/87824
13.
Cao, Lingling.
Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials.
Degree: Docteur es, Mathématiques, 2019, Université Paris-Est
URL: http://www.theses.fr/2019PESC1028
► Cette thèse porte sur l’analyse mathématique de modèles de structures électroniques de matériaux présentant des défauts, elle contient trois sujets différents. Dans le chapitre 2,…
(more)
▼ Cette thèse porte sur l’analyse mathématique de modèles de structures électroniques de matériaux présentant des défauts, elle contient trois sujets différents. Dans le chapitre 2, nous étudions l’état fondamental d’un défaut étendu dans une mer de Fermi. Dans le chapitre 3, nous nous intéressons à la description mathématique de la jonction de deux matériaux quasi unidimensionnels. Dans le chapitre 4, nous construisons un cadre mathématique pour la dynamique d’un réseau cristallin de taille infinie, dans l’approximation de Born-Oppenheimer, dans laquelle l’électron est couplé à la dynamique nucléaire
This thesis focuses on the mathematical analysis of electronic structure models for materials with defects.It contains three different topics. In Chapter 2 we study the ground state of an extended defect in a Fermisea. In Chapter 3 we are interested in the mathematical description of the junction of two perfect quasi onedimensional materials. In Chapter 4 we construct a mathematical framework for a lattice dynamics underthe Born-Oppenheimer approximation, where electrons are coupled with the nuclear dynamics
Advisors/Committee Members: Cancès, Eric (thesis director), Stoltz, Gabriel (thesis director).
Subjects/Keywords: Analyse mathématique; Structures électroniques; Matériaux avec défauts; Mathematical analysis; Electronic structures; Defected materials; 510
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Cao, L. (2019). Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2019PESC1028
Chicago Manual of Style (16th Edition):
Cao, Lingling. “Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials.” 2019. Doctoral Dissertation, Université Paris-Est. Accessed March 01, 2021.
http://www.theses.fr/2019PESC1028.
MLA Handbook (7th Edition):
Cao, Lingling. “Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials.” 2019. Web. 01 Mar 2021.
Vancouver:
Cao L. Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials. [Internet] [Doctoral dissertation]. Université Paris-Est; 2019. [cited 2021 Mar 01].
Available from: http://www.theses.fr/2019PESC1028.
Council of Science Editors:
Cao L. Analyse mathématique de modèles de structures électroniques de matériaux avec défauts : Mathematical analysis of electronic structure models for defected materials. [Doctoral Dissertation]. Université Paris-Est; 2019. Available from: http://www.theses.fr/2019PESC1028

Cal Poly
14.
Carter, Jeffrey Scott.
Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures.
Degree: MS, Aerospace Engineering, 2014, Cal Poly
URL: https://digitalcommons.calpoly.edu/theses/1327
;
10.15368/theses.2014.164
► The use of composite sandwich structures is rapidly increasing in the aerospace industry because of their increased strength-to-weight and stiffness-to-weight characteristics. The effects of…
(more)
▼ The use of composite sandwich
structures is rapidly increasing in the aerospace industry because of their increased strength-to-weight and stiffness-to-weight characteristics. The effects of low velocity impacts on these
structures, however, are the main weakness that hinders further use of them in the industry because the damages from these loadings can often be catastrophic. Impact behavior of composite
materials in general is a crucial consideration for a designer but can be difficult to describe theoretically. Because of this, experimental analysis is typically used to attempt to describe the behavior of composite sandwiches under impact loads. Experimental testing can still be unpredictable, however, because low velocity impacts can cause undetectable damage within the composites that weaken their structural integrity. This is an important issue with composite sandwich
structures because interlaminar damage within the composite facesheets is typical with composites but the addition of a core material results in added failure modes. Because the core is typically a weaker material than the surrounding facesheet material, the core is easily damaged by the impact loads. The adhesion between the composite facesheets and the core material can also be a major region of concern for sandwich
structures. Delamination of the facesheet from the core is a major issue when these
structures are subjected to impact loads.
This study investigated, through experimental and numerical analysis, how varying the core and facesheet material combination affected the flexural strength of a composite sandwich subjected to low velocity impact. Carbon, hemp, aramid, and glass fiber
materials as facesheets combined with honeycomb and foam as core
materials were considered. Three layers of the same composite material were laid on the top and bottom of the core material to form each sandwich structure. This resulted in eight different sandwich designs. The carbon fiber/honeycomb sandwiches were then combined with the aramid fiber facesheets, keeping the same three layer facesheet design, to form two hybrid sandwich designs. This was done to attempt to improve the impact resistance and post-impact strength characteristics of the carbon fiber sandwiches. The two and one layer aramid fiber laminates on these hybrid sandwiches were always laid up on the outside of the structure. The sandwiches were cured using a composite press set to the recommended curing cycle for the composite facesheet material. The hybrid sandwiches were cured twice for the two different facesheet
materials. The cured specimens were then cut into 3 inch by 10 inch sandwiches and 2/3 of them were subjected to an impact from a 7.56 lbf crosshead which was dropped from a height of 38.15 inches above the bottom of the specimen using a Dynatup 8250 drop weight machine.
The impacted specimen and the control specimen (1/3 of the specimens not subjected to an impact) were loaded in a four-point bend test per ASTM D7250 to determine the non-impacted and post-impact…
Advisors/Committee Members: Dr. Faysal Kolkailah.
Subjects/Keywords: Aerospace Engineering; Composite Materials; Composite Sandwich Structures; Impact Testing; Four-Point Bend Testing; Structures and Materials
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Carter, J. S. (2014). Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures. (Masters Thesis). Cal Poly. Retrieved from https://digitalcommons.calpoly.edu/theses/1327 ; 10.15368/theses.2014.164
Chicago Manual of Style (16th Edition):
Carter, Jeffrey Scott. “Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures.” 2014. Masters Thesis, Cal Poly. Accessed March 01, 2021.
https://digitalcommons.calpoly.edu/theses/1327 ; 10.15368/theses.2014.164.
MLA Handbook (7th Edition):
Carter, Jeffrey Scott. “Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures.” 2014. Web. 01 Mar 2021.
Vancouver:
Carter JS. Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures. [Internet] [Masters thesis]. Cal Poly; 2014. [cited 2021 Mar 01].
Available from: https://digitalcommons.calpoly.edu/theses/1327 ; 10.15368/theses.2014.164.
Council of Science Editors:
Carter JS. Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich Structures. [Masters Thesis]. Cal Poly; 2014. Available from: https://digitalcommons.calpoly.edu/theses/1327 ; 10.15368/theses.2014.164

NSYSU
15.
Chang, Hsiao-wen.
Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures.
Degree: PhD, Physics, 2015, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1124114-185048
► This thesis investigates the magnetotransport properties of ultrathin (Ga,Mn)Sb layers in a field-effect structure. We fabricate a metal-insulator-semiconductor field-effect structure with a thin (Ga,Mn)Sb channel…
(more)
▼ This thesis investigates the magnetotransport properties of ultrathin (Ga,Mn)Sb layers in a field-effect structure. We fabricate a metal-insulator-semiconductor field-effect structure with a thin (Ga,Mn)Sb channel and investigate its magnetotransport properties, as functions of temperature, external magnetic field, and gate electric field. The results show that one can control magnetic properties of (Ga,Mn)Sb by applying electric fields, as similar to (Ga,Mn)As. The most prominent finding is that the Curie temperature of (Ga,Mn)Sb can be modulated by gating but in somewhat different manner from (Ga,Mn)As. For (Ga,Mn)Sb, we determine experimentally the relationship between the Curie temperature TC and hole concentration p, to be Tc â p^Ï with Ï of 1.3~1.6, which is several times larger than Ï ~ 0.2 reported previously for (Ga,Mn)As.
We show that the value of Ï can be reproduced by the numerical calculations based on the adapted p-d Zener model with non-uniform hole distribution, and the calculation indicates the accumulation of holes in (Ga,Mn)Sb in the vicinity of the interface with a gate insulator, while for (Ga,Mn)As the depletion of holes at the interface. The results are consistent with the reported Fermi energy pinning positions for p-GaSb and p-GaAs.
We also find that the conductivity dependence of the Hall conductivity is different from that reported for (Ga,Mn)As.
The findings are of great importance for employing thin and ultrathin layers of (Ga,Mn)Sb or related compounds in the concept of spintronics devices, where magnetic and electronic properties are mutually controlled.
Advisors/Committee Members: Tsung-Wei Chen (chair), Jung-Chun Hung (chair), Fumihiro Matsukura (committee member), Quark Yung-Sung Chen (chair), Hideo Ohno (committee member), Hsiung Chou (committee member), Shih-Jye Sun (chair).
Subjects/Keywords: Magnetic materials; Field effect structures; Semiconducting IIIâV materials; Antimonides; Molecular beam epitaxy
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APA (6th Edition):
Chang, H. (2015). Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures. (Doctoral Dissertation). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1124114-185048
Chicago Manual of Style (16th Edition):
Chang, Hsiao-wen. “Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures.” 2015. Doctoral Dissertation, NSYSU. Accessed March 01, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1124114-185048.
MLA Handbook (7th Edition):
Chang, Hsiao-wen. “Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures.” 2015. Web. 01 Mar 2021.
Vancouver:
Chang H. Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures. [Internet] [Doctoral dissertation]. NSYSU; 2015. [cited 2021 Mar 01].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1124114-185048.
Council of Science Editors:
Chang H. Electric-Field Effects on Magnetic Properties of (Ga,Mn)Sb Channel in Field-Effect Structures. [Doctoral Dissertation]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1124114-185048

University of California – Merced
16.
Diaz Moreno, Miguel Fernando.
An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms.
Degree: Biological Engineering and Small-scale Technologies, 2015, University of California – Merced
URL: http://www.escholarship.org/uc/item/3g83t614
► Diatoms are microscopic algae featuring porous cell wall structures (frustules). Due to the wide variety of diatom shapes and intricate architectures, diatom frustules are viable…
(more)
▼ Diatoms are microscopic algae featuring porous cell wall structures (frustules). Due to the wide variety of diatom shapes and intricate architectures, diatom frustules are viable prototypes to guide the design and fabrication of nanodevices for applications ranging from sensors to nanotemplates. The porous structure and mechanical behavior of biosilica diatom frustules were evaluated through ambient nanoindentation, AFM-based nanoindentation and finite element method (FEM) analysis. Two diatom species, Coscinodiscus sp. (centric) and Synedra sp. (pennate), were investigated through ambient nanoindentation and FEM simulation. High-resolution microscopy unveiled the diatom species structures. These diatom frustule dimensions varied largely depending on diatom species (diameters from 70-250 μm and lengths from 100-300 μm) with pore diameters ranging from 0.1-3.0 μm. Young’s modulus E and hardness H of the diatom frustules were obtained via ambient nanoindentation. These values varied also depending on diatom species: E from 1.1-10.6 GPa, H from 0.10-1.03 GPa for the Coscinodiscus sp.; and E from 13.7-18.6 GPa, H from 0.85-1.41 GPa for the Synedra sp. Predictive FEM simulations were performed on well-validated 3D frustule models, to correlate the mechanical response with specific morphology variables such as pore sizes. A correlation between mechanical properties and porosity was established for selected frustules. Furthermore, AFM investigation and FEM simulation involving 3D frustule models with hierarchical geometries were achieved to investigate the structure-property relationship upon compressive loads. AFM imaging and AFM-based nanoindentation of the centric and pennate frustules provided surface morphology and associated load-displacement curves, which were used to further characterize the diatoms. The calculated average E was 21.5 GPa and 26 GPa for the Coscinodiscus sp. and Synedra sp. respectively, which are higher than the values obtained from ambient nanoindentation. FEM compression simulations were also performed on centric models only to study the role of the hierarchical structures on their mechanical response. Displacement and stress distributions of a three-layered hierarchical frustule model under varied loads were systematically investigated. Results were compared with a stacking of three porous layers for further discussion. Suggestions for future experiments and modeling efforts are provided to enhance the ability to map strategies for the fabrication of 3D nanostructures and nanodevices.
Subjects/Keywords: Materials Science; Nanoscience; Engineering; Bioinspired materials; Diatoms; FEM simulations; Hierarchical structures; Nanomechanical experiment
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APA (6th Edition):
Diaz Moreno, M. F. (2015). An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms. (Thesis). University of California – Merced. Retrieved from http://www.escholarship.org/uc/item/3g83t614
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):
Diaz Moreno, Miguel Fernando. “An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms.” 2015. Thesis, University of California – Merced. Accessed March 01, 2021.
http://www.escholarship.org/uc/item/3g83t614.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Diaz Moreno, Miguel Fernando. “An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms.” 2015. Web. 01 Mar 2021.
Vancouver:
Diaz Moreno MF. An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms. [Internet] [Thesis]. University of California – Merced; 2015. [cited 2021 Mar 01].
Available from: http://www.escholarship.org/uc/item/3g83t614.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Diaz Moreno MF. An Integrated Study of the Porous Structure and Mechanical Properties of Diatoms. [Thesis]. University of California – Merced; 2015. Available from: http://www.escholarship.org/uc/item/3g83t614
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Cal Poly
17.
Hallak, Yanina Soledad.
DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT.
Degree: MS, Aerospace Engineering, 2016, Cal Poly
URL: https://digitalcommons.calpoly.edu/theses/1572
;
10.15368/theses.2016.49
► CubeSats, specially the 6U standard, is nowadays the tendency where many developers point towards. The upscaling size of the standard and payloads entail the…
(more)
▼ CubeSats, specially the 6U standard, is nowadays the tendency where many developers point towards. The upscaling size of the standard and payloads entail the increase of the satellite overall mass. Composite
materials have demonstrated the ability to fulfill expectations like reducing structural masses, having been applied to different types of spacecraft, including small satellites.
This Thesis is focused on designing, manufacturing, and dynamic testing of a 6U CubeSat made of carbon fiber, fiberglass, and aluminum.
The main objective of this study was obtaining a mass reduction of a 6U CubeSat structure, maintaining the stiffness and strength. Considering the thermal effects of the used
materials an outgassing test of the used
materials was performed and the experimental results are presented.
The CubeSat structure was entirely manufactured and tested at Cal Poly Aerospace Engineering Department facilities. A mechanical shock test and random vibration test were performed using a shock table and a shake table respectively. Results of both tests are presented. A correlation between the Experimental data and the Finite Element Model of the satellite was carried out. Finally, a comparison between 6U structure studied and aluminum 6U
structures available in the market is presented.
Advisors/Committee Members: Dr Faysal Kolkailah.
Subjects/Keywords: CubeSat; Random Vibration; Mechanical Shock; Composite Materials; Finite Element Analysis; Small Satellites; Structures and Materials
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Hallak, Y. S. (2016). DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT. (Masters Thesis). Cal Poly. Retrieved from https://digitalcommons.calpoly.edu/theses/1572 ; 10.15368/theses.2016.49
Chicago Manual of Style (16th Edition):
Hallak, Yanina Soledad. “DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT.” 2016. Masters Thesis, Cal Poly. Accessed March 01, 2021.
https://digitalcommons.calpoly.edu/theses/1572 ; 10.15368/theses.2016.49.
MLA Handbook (7th Edition):
Hallak, Yanina Soledad. “DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT.” 2016. Web. 01 Mar 2021.
Vancouver:
Hallak YS. DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT. [Internet] [Masters thesis]. Cal Poly; 2016. [cited 2021 Mar 01].
Available from: https://digitalcommons.calpoly.edu/theses/1572 ; 10.15368/theses.2016.49.
Council of Science Editors:
Hallak YS. DESIGN, MANUFACTURE, DYNAMIC TESTING, AND FINITE ELEMENT ANALYSIS OF A COMPOSITE 6U CUBESAT. [Masters Thesis]. Cal Poly; 2016. Available from: https://digitalcommons.calpoly.edu/theses/1572 ; 10.15368/theses.2016.49

Utah State University
18.
Christensen, Justin.
Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials.
Degree: MS, Physics, 2017, Utah State University
URL: https://digitalcommons.usu.edu/etd/6694
► Materials exposed to the space plasma environment acquire electric charge, which can have harmful effects if it leads to arcing or electrostatic breakdown of…
(more)
▼ Materials exposed to the space plasma environment acquire electric charge, which can have harmful effects if it leads to arcing or electrostatic breakdown of important spacecraft components. In fact, spacecraft charging is the leading environmentally induced cause of spacecraft anomalies. This study focuses on measuring electron yield, a property of
materials that describes how many electrons are ejected from a material under energetic electron bombardment, which can vary depending on the energy of incident electrons. Intrinsic electron yield is defined as the average number of electrons emitted per incident electron from an electrically neutral material. The specific aim of this work is to improve yield measurements for insulator
materials, which can be difficult to test using conventional methods due to charge accumulation in insulators.Most studies of electron yield use a steady current electron beam in a vacuum chamber to irradiate
materials to be tested. By comparing the amount of current deposited in the material to the total incident current, the emitted current can be calculated. This works well for conductors; however, insulators charge up quickly, which either repel incident electrons or reattract emitted electrons producing erroneous yield measurements. This study improves on methods that use a pulsed electron beam to measure yield with small amounts of charge per pulse, as well as neutralization methods to dissipate stored charge between pulse measurements.The improvements to instrumentation and data analysis techniques are quantified to demonstrate their validity. These improvements will allow for continued studies on extreme insulator
materials. Future studies will provide new understanding of interactions between electron radiation and
materials, which will allow for better modeling of spacecraft charging and the development of
materials that meet desired electron emission specifications.
Advisors/Committee Members: JR Dennison, D Mark Riffe, Farrell Edwards, ;.
Subjects/Keywords: Electron Yield; Charge Neutralization; Space Environment; Insulating Materials; Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Christensen, J. (2017). Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials. (Masters Thesis). Utah State University. Retrieved from https://digitalcommons.usu.edu/etd/6694
Chicago Manual of Style (16th Edition):
Christensen, Justin. “Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials.” 2017. Masters Thesis, Utah State University. Accessed March 01, 2021.
https://digitalcommons.usu.edu/etd/6694.
MLA Handbook (7th Edition):
Christensen, Justin. “Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials.” 2017. Web. 01 Mar 2021.
Vancouver:
Christensen J. Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials. [Internet] [Masters thesis]. Utah State University; 2017. [cited 2021 Mar 01].
Available from: https://digitalcommons.usu.edu/etd/6694.
Council of Science Editors:
Christensen J. Electron Yield Measurements of High-Yield, Low-Conductivity Dielectric Materials. [Masters Thesis]. Utah State University; 2017. Available from: https://digitalcommons.usu.edu/etd/6694

Stellenbosch University
19.
Neethling, Christoffel Johannes.
Evaluation of bio-inspired composite structures for impact materials.
Degree: MEng, Mechanical and Mechatronic Engineering, 2016, Stellenbosch University
URL: http://hdl.handle.net/10019.1/98598
Subjects/Keywords: Impact materials; Bio-inspired composite structures – Evaluation; UCTD
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Chicago ·
MLA ·
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Export
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APA (6th Edition):
Neethling, C. J. (2016). Evaluation of bio-inspired composite structures for impact materials. (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/98598
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):
Neethling, Christoffel Johannes. “Evaluation of bio-inspired composite structures for impact materials.” 2016. Thesis, Stellenbosch University. Accessed March 01, 2021.
http://hdl.handle.net/10019.1/98598.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Neethling, Christoffel Johannes. “Evaluation of bio-inspired composite structures for impact materials.” 2016. Web. 01 Mar 2021.
Vancouver:
Neethling CJ. Evaluation of bio-inspired composite structures for impact materials. [Internet] [Thesis]. Stellenbosch University; 2016. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10019.1/98598.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Neethling CJ. Evaluation of bio-inspired composite structures for impact materials. [Thesis]. Stellenbosch University; 2016. Available from: http://hdl.handle.net/10019.1/98598
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

North Carolina State University
20.
Burgun, Robert Scott.
The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform.
Degree: MS, Aerospace Engineering, 2003, North Carolina State University
URL: http://www.lib.ncsu.edu/resolver/1840.16/1158
► An uninhabited aero vehicle platform design is presented. This encompasses the landing gear system and the structures of the vehicle. The landing gear system consisted…
(more)
▼ An uninhabited aero vehicle platform design is presented. This encompasses the landing gear system and the
structures of the vehicle. The landing gear system consisted of the design, construction and testing of the main and nose gears. The testing of the landing gear resulted in a valid system that could then be integrated into the vehicle. The vehicle
structures are composed of various configurations of composite sandwiches. Extensive material testing was conducted to experimentally produce the physical properties of the
materials. These properties and techniques can be utilized by other vehicle designs. The structural design was refined and ultimately verified within a finite element analysis program, ANSYS. This analysis implemented a composite shell element that utilized all of the material properties gained from the material testing. This work resulted in an analyzed and constructed vehicle. Ultimately the vehicle was load tested to verify the analytical results.
Advisors/Committee Members: Dr. James Selgrade, Committee Member (advisor), Dr. Eric Klang, Committee Member (advisor), Dr. Charles E. Hall Jr, Committee Chair (advisor).
Subjects/Keywords: UAV; Structures; Composite Materials
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Burgun, R. S. (2003). The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform. (Thesis). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/1158
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):
Burgun, Robert Scott. “The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform.” 2003. Thesis, North Carolina State University. Accessed March 01, 2021.
http://www.lib.ncsu.edu/resolver/1840.16/1158.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Burgun, Robert Scott. “The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform.” 2003. Web. 01 Mar 2021.
Vancouver:
Burgun RS. The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform. [Internet] [Thesis]. North Carolina State University; 2003. [cited 2021 Mar 01].
Available from: http://www.lib.ncsu.edu/resolver/1840.16/1158.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Burgun RS. The Design, Analysis, Construction and Testing of an Uninhabited Aero Vehicle Platform. [Thesis]. North Carolina State University; 2003. Available from: http://www.lib.ncsu.edu/resolver/1840.16/1158
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto
21.
Jeronimo, David Mark.
Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials.
Degree: 2014, University of Toronto
URL: http://hdl.handle.net/1807/68081
► Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded…
(more)
▼ Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 µm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.
M.A.S.
Advisors/Committee Members: Guenther, Axel, Biomedical Engineering.
Subjects/Keywords: 3D Bioprinting; Hydrogels; Perfusable Materials; Tubular Structures; 0541
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APA ·
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Export
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APA (6th Edition):
Jeronimo, D. M. (2014). Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/68081
Chicago Manual of Style (16th Edition):
Jeronimo, David Mark. “Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials.” 2014. Masters Thesis, University of Toronto. Accessed March 01, 2021.
http://hdl.handle.net/1807/68081.
MLA Handbook (7th Edition):
Jeronimo, David Mark. “Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials.” 2014. Web. 01 Mar 2021.
Vancouver:
Jeronimo DM. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials. [Internet] [Masters thesis]. University of Toronto; 2014. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1807/68081.
Council of Science Editors:
Jeronimo DM. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials. [Masters Thesis]. University of Toronto; 2014. Available from: http://hdl.handle.net/1807/68081

University of Toronto
22.
Chen, Haotian.
One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels.
Degree: 2014, University of Toronto
URL: http://hdl.handle.net/1807/68576
► Tubular structures are fundamental constituents of plant, animal and human tissues. Synthetically prepared biomaterial tubular constructs have a variety of applications that include engineered blood…
(more)
▼ Tubular structures are fundamental constituents of plant, animal and human tissues. Synthetically prepared biomaterial tubular constructs have a variety of applications that include engineered blood vessels, vascularized biomaterials as well as soft robotic actuators. Currently there is no one-step method for the scalable preparation of perfusable tubular soft materials that allows the tube size, morphology, composition and tensile properties to be consistently altered. We report a scalable microfluidic approach for the consistent formation of cross-linked biopolymer tubes in sodium alginate and collagen I, with outer diameters between 0.7 mm and 2.5 mm, at extrusion velocities between 1mm/s and 20mm/s. We report the consistent formation of homogeneous tubes with cylindrical, crimped, and corkscrew inner wall surfaces. Heterotypic tubular constructs possess up to three concentric wall layers, or consist of single-layered "Janus" tubes and tubes with incorporated axial stripe patterns. Fluorescent microspheres and swelling nanoparticles were incorporated as payload and allowed us to image the tube architecture and induce predictive shape transformations. This research can potentially lead to high throughput construction of complex spatially organized 3D functional soft materials and tissues.
M.A.S.
Advisors/Committee Members: Guenther, Axel, Biomedical Engineering.
Subjects/Keywords: Bioprinting; Hydrogels; Soft materials; Spatial heterogeneities; Stimulus Responsive; Tubular structures; 0541
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chen, H. (2014). One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/68576
Chicago Manual of Style (16th Edition):
Chen, Haotian. “One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels.” 2014. Masters Thesis, University of Toronto. Accessed March 01, 2021.
http://hdl.handle.net/1807/68576.
MLA Handbook (7th Edition):
Chen, Haotian. “One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels.” 2014. Web. 01 Mar 2021.
Vancouver:
Chen H. One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels. [Internet] [Masters thesis]. University of Toronto; 2014. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/1807/68576.
Council of Science Editors:
Chen H. One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels. [Masters Thesis]. University of Toronto; 2014. Available from: http://hdl.handle.net/1807/68576

Colorado State University
23.
Peterson, Kirsten LaRhea.
Mechanics of plastic-aluminum composite I-beams, The.
Degree: MS(M.S.), Civil and Environmental Engineering, 2014, Colorado State University
URL: http://hdl.handle.net/10217/82630
► This thesis presents an initial investigation of the mechanics of I-beams developed with plastic-aluminum composite technology. Plastic-aluminum composites in structural beam/frame/truss elements are a relatively…
(more)
▼ This thesis presents an initial investigation of the mechanics of I-beams developed with plastic-aluminum composite technology. Plastic-aluminum composites in structural beam/frame/truss elements are a relatively new concept that has seen little, if any, application in modern construction. This technology has considerable potential to add innovative choices to the array of
materials currently available in the construction industry. Several new tests were designed and performed on different portions of the beams, including Push-Through and Knit-Line Pull tests, and tensile tests per ASTM D638-10. The results of these tests showed increased strength with an increase of talc filler content and also showed that the addition of a metal deactivator additive to the plastic results in a slight increase in strength. Duration of Load tests were performed per ASTM D7031-04 and none of the beams tested exhibit tertiary creep. The I-beams investigated here use an internal shear connector (deboss) which acts as a mechanical fastener between the aluminum and the flange plastic. A numerical finite element model was developed in ABAQUS to better understand the underlying physics of the deboss and was compared with a Push-Through test specimen. The results from the model closely match experimental results and the model can be used to predict within 10% the load per deboss region that can be resisted before the plastic begins to yield and extensively deform. This model can be used for differing deboss geometries and any plastic with known material properties. Overall, the results of this research support potential future research involving a more in-depth investigation of this innovative, new class of material technology for use as a structural material.
Advisors/Committee Members: Heyliger, Paul (advisor), Atadero, Rebecca (committee member), Leisure, Robert (committee member).
Subjects/Keywords: beam mechanics; structures; plastic-metal composites; I-beams; composite materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Peterson, K. L. (2014). Mechanics of plastic-aluminum composite I-beams, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/82630
Chicago Manual of Style (16th Edition):
Peterson, Kirsten LaRhea. “Mechanics of plastic-aluminum composite I-beams, The.” 2014. Masters Thesis, Colorado State University. Accessed March 01, 2021.
http://hdl.handle.net/10217/82630.
MLA Handbook (7th Edition):
Peterson, Kirsten LaRhea. “Mechanics of plastic-aluminum composite I-beams, The.” 2014. Web. 01 Mar 2021.
Vancouver:
Peterson KL. Mechanics of plastic-aluminum composite I-beams, The. [Internet] [Masters thesis]. Colorado State University; 2014. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10217/82630.
Council of Science Editors:
Peterson KL. Mechanics of plastic-aluminum composite I-beams, The. [Masters Thesis]. Colorado State University; 2014. Available from: http://hdl.handle.net/10217/82630

Edith Cowan University
24.
Wild, Graham.
Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles.
Degree: 2010, Edith Cowan University
URL: https://ro.ecu.edu.au/theses/1873
► The use of distributed optical fibre smart sensors for the detection of acoustic signals in the Structural Health Monitoring (SHM) of robust aerospace vehicles has…
(more)
▼ The use of distributed optical fibre smart sensors for the detection of acoustic signals in the Structural Health Monitoring (SHM) of robust aerospace vehicles has been demonstrated. Current distributed optical fibre sensors are multiplexed along a single fibre. Inherent problems exist with a multiplexed architecture. Two significant issues are; the possibility of fibre breakage, and the possibility of failure of the single transmitter, the single receiver, or the single processor. In a ‘smart’ architecture, the intelligence, as well as the sensors, is distributed. Hence, if destructive damage occurs, then the SHM system can continue to operate in all other locations on the vehicle, making the system robust.
Work on the optical fibre sensors was limited to acoustic signals. This included acoustic emissions, acousto-ultrasonics, acoustic transmissions and other dynamic strain signals. Fibre Bragg Gratings (FBGs) were chosen as the optical fibre sensor for the detection of the acoustic signals. FBGs offer significant advantages over other types of optical fibre sensors. The most significant of these is the ease of multiplexing and their versatility, i.e. the ability of FBGs to detect a significant number of measurands. In the work on optical fibre sensing, we showed the implementation of an innovative detection system. This Transmit Reflect Detection System (TRDS) made use of both the transmitted and reflected signals from the FBG. The TRDS is an improvement on conventional power detection where either the transmitted or reflected component is used. The TRDS was used to successfully detect all types of dynamic and static signals, the most significant being the acoustic emission from a lead pencil break test.
The use of the FBG sensor as a receiver for acoustic communications was also shown. Acoustic communications have been proposed for use in the SHM of robust aerospace vehicles with the use of autonomous agents, e.g. inspection or repair robots. The FBG receivers were compared with PZT receivers. When communicating through aluminium, the FBG performance was not as good as the PZT receiver, specifically due to the properties of the FBG which limit the frequency response. However, in Carbon Fibre Composites (CFC), the FBG outperformed the PZT due to the properties of the CFC. We also note that when contained within the thermal packaging the FBG had a very interesting frequency response, likely due to the suspended beam nature of the structure. This type of packaging could be used to tune the response of the FBG sensor.
The work on the distributed optical fibre smart sensors showed the implementation of a Smart Transducer Interface Module (STIM), which used the TRDS with a Digital Signal Processor (DSP). The output of the TRDS was differentially amplified with a high speed amplifier, and the output was passed to the ADC onboard the DSP. The DSP was also used to toggle on and off output, including closed loop actuation, and controlling a 1550nm laser, which would represent the source used in the implemented system. The…
Subjects/Keywords: Aerospace vehicles; optical fibre; autonomous; Aerospace Engineering; Structures and Materials
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MLA ·
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APA (6th Edition):
Wild, G. (2010). Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles. (Thesis). Edith Cowan University. Retrieved from https://ro.ecu.edu.au/theses/1873
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):
Wild, Graham. “Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles.” 2010. Thesis, Edith Cowan University. Accessed March 01, 2021.
https://ro.ecu.edu.au/theses/1873.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wild, Graham. “Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles.” 2010. Web. 01 Mar 2021.
Vancouver:
Wild G. Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles. [Internet] [Thesis]. Edith Cowan University; 2010. [cited 2021 Mar 01].
Available from: https://ro.ecu.edu.au/theses/1873.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wild G. Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles. [Thesis]. Edith Cowan University; 2010. Available from: https://ro.ecu.edu.au/theses/1873
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Embry-Riddle Aeronautical University
25.
Rovik, Christopher Lee.
Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks.
Degree: MSin Aerospace Engineering, Graduate Studies, 1998, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/db-theses/231
► The research encompassed within this paper deals with the analysis and classification of fatigue cracks in aircraft structures. The particular structure that was examined…
(more)
▼ The research encompassed within this paper deals with the analysis and classification of fatigue cracks in aircraft
structures. The particular structure that was examined was the vertical tail section of a Cessna T-303 Crusader aircraft. The analysis was performed using the nondestructive evaluation technique known as acoustic emission (AE), as well as the artificial intelligence of neural networks. Data were taken in a controlled laboratory environment as well as in a flying testbed aboard the aircraft.
The first part of the research involved the analysis of a typical aircraft structure in a controlled laboratory environment. This support structure was fabricated from 7075-T6 aluminum, which is common in aircraft
structures. Two different methods were used to fatigue the support, an MTS tensile test machine and a shaker table. Extensive AE data were taken throughout the laboratory tests in order to provide a known reference for the identification of fatigue cracks.
The acoustic emission data derived from the laboratory tests were thoroughly examined and sorted into three distinct mechanisms: fatigue cracking, plastic deformation, and mechanical noise. The AE parameters associated with these mechanisms were in turn used to train a neural network. The neural network used was the Kohonen self-organizing map, as it is an excellent choice for the purpose of classification.
Once the neural network was trained, it was possible to proceed to the second stage of the research. A support structure, identical to the one used in the laboratory tests, was installed in the vertical tail of the T-303 aircraft. Acoustic emission data were gathered during all aspects of aircraft maneuvers, from the initial taxiing and takeoff to the final approach and landing, including rolls and Dutch rolls.
The AE parameters recorded from the in-flight tests were processed using the neural network trained in the first part of the research. Thus, the data were classified as being indicative of fatigue cracking, plastic deformation, or rubbing. These mechanisms were then analyzed with respect to the particular maneuver performed to further understand the stresses associated with different maneuvers. As a result of the ability to classify fatigue cracks, it is possible to develop a monitoring system for aircraft to determine the existence of fatigue cracks before they grow to the point where they become dangerous.
Advisors/Committee Members: Dr. Eric v. K. Hill, Dr. Frank J. Radosta, Dr. James G. Ladesic.
Subjects/Keywords: Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Rovik, C. L. (1998). Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/db-theses/231
Chicago Manual of Style (16th Edition):
Rovik, Christopher Lee. “Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks.” 1998. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/db-theses/231.
MLA Handbook (7th Edition):
Rovik, Christopher Lee. “Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks.” 1998. Web. 01 Mar 2021.
Vancouver:
Rovik CL. Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 1998. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/db-theses/231.
Council of Science Editors:
Rovik CL. Classification of In-Flight Fatigue Cracks in Aircraft Structures using Acoustic Emission and Neural Networks. [Masters Thesis]. Embry-Riddle Aeronautical University; 1998. Available from: https://commons.erau.edu/db-theses/231

Embry-Riddle Aeronautical University
26.
Nguyen, Tuan-Khoi Dang.
Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact.
Degree: Master of Aerospace Engineering, Graduate Studies, 2005, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/db-theses/248
► Composite materials have become one of the leading materials for manufacturing in the aerospace industry today. Compared to "conventional" aerospace metals, composites generally have…
(more)
▼ Composite
materials have become one of the leading
materials for manufacturing in the aerospace industry today. Compared to "conventional" aerospace metals, composites generally have higher strength-to-weight and stiffness-to-weight ratios, good fatigue and corrosion resistance and reduced parts count. However, like any other material, they also have disadvantages. They are inherently brittle and are thus prone to impact damage. Low energy/velocity impact damage, in particular, can be dangerous because the damage oftentimes goes undetected and can subsequently grow under load. Also known as barely visible impact damage (BVID), this area of concentration focuses on the small-scale damage that may be very difficult to detect yet can be lethal.
The primary emphasis of this research is to predict the residual compressive strength of a 16-ply laminate [(0°/±45°/90°)2]s after experiencing low energy/velocity impact using combined technical approaches of ultrasonic C-scan and neural networks. To accomplish this, each test specimen was ultrasonically C-scanned after impact testing. A MATLAB computer program was then used to convert the image files into numeric data, which they were presented to a backpropagation neural network in order to predict the residual compressive strength. Microsoft Excel was used to take the average of the diagonal values of the normalized image data. Here the average prediction error turned out to be 3.9 percent, while the worst-case prediction error was 14.6 percent.
This research also focused on identifying, sorting, and classifying how the composite laminates failed under compression after experiencing low energy/low velocity impact. Acoustic emission (AE) parameter data were collected during compression testing, and then inputted into an artificial neural network (ANN) for classification. Specifically a Kohonen Self Organizing Map (SOM) was used to sort and classify the failure mechanisms that occurred within the weakened composites. The associated BVID failure modes, otherwise known as failure mechanisms, were believed to consist primarily of transverse and longitudinal matrix cracks, delaminations, and occasionally fiber breaks. Even though delaminations are the most critical failure modes in BVID under compression, the other failure mechanisms also contribute significantly. Furthermore, it appeared that it was also possible to sort out and determine the transition regions between BVID and visible impact damage (VID) with AE data. Thus, it is important to know how the material fails so that necessary precautions can be taken to minimize these critical failure modes.
Advisors/Committee Members: Dr. Yi Zhao, Dr. Eric v. K. Hill, Dr. David J. Sypeck.
Subjects/Keywords: Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Nguyen, T. D. (2005). Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/db-theses/248
Chicago Manual of Style (16th Edition):
Nguyen, Tuan-Khoi Dang. “Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact.” 2005. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/db-theses/248.
MLA Handbook (7th Edition):
Nguyen, Tuan-Khoi Dang. “Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact.” 2005. Web. 01 Mar 2021.
Vancouver:
Nguyen TD. Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 2005. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/db-theses/248.
Council of Science Editors:
Nguyen TD. Damage Assessment and Strength Predictions in S-Glass/Epoxy Laminates Subjected to Low Energy Impact. [Masters Thesis]. Embry-Riddle Aeronautical University; 2005. Available from: https://commons.erau.edu/db-theses/248

Embry-Riddle Aeronautical University
27.
Thornton, Weldon Paul.
Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map.
Degree: MSin Aerospace Engineering, Aerospace Engineering, 1995, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/db-theses/198
► Acoustic emission nondestructive testing has been used for real-time monitoring of complex structures. All of the structures were made of materials at least 0.070…
(more)
▼ Acoustic emission nondestructive testing has been used for real-time monitoring of complex
structures. All of the
structures were made of
materials at least 0.070 inch thick. The purpose of this research was to demonstrate the feasibility of using neural networks to classify acoustic emission signals gathered from a pressure vessel made of 2024-T3 aluminum 0.040 inches thick, i.e. thin aluminum sheet. AE waveforms were recorded during fatigue cycling of one pressure vessel using a wide band transducer and a digital oscilloscope connected to a computer. The source for each signal was determined using two narrow band transducers and a LOCAN-AT data acquisition system. The power spectrum was calculated for each waveform. A Kohonen self-organizing map (SOM) was used to cluster the spectra. The network clustered the data on a two-dimensional feature space according to the source of the signal. A total of 3,600 power spectra were used to train the neural network, and 1,800 were used to test the network. Initially there was overlap between the clusters on the two-dimensional feature space; however, this was found to be due to human error. The SOM itself correctly classified all of the signals.
Advisors/Committee Members: Dr. Eric v. K. Hill, Dr. Frank Radosta, Dr. Sathya Gangadharan.
Subjects/Keywords: Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Thornton, W. P. (1995). Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/db-theses/198
Chicago Manual of Style (16th Edition):
Thornton, Weldon Paul. “Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map.” 1995. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/db-theses/198.
MLA Handbook (7th Edition):
Thornton, Weldon Paul. “Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map.” 1995. Web. 01 Mar 2021.
Vancouver:
Thornton WP. Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 1995. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/db-theses/198.
Council of Science Editors:
Thornton WP. Classification of Acoustic Emission Signals from an Aluminum Pressure Vessel Using a Self-Organizing Map. [Masters Thesis]. Embry-Riddle Aeronautical University; 1995. Available from: https://commons.erau.edu/db-theses/198

Embry-Riddle Aeronautical University
28.
Savella, Philip A.
Maneuvering Control of a Spacecraft with Propellant Sloshing.
Degree: MSin Space Science, Physical Sciences, 2005, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/db-theses/178
► Propellant slosh has been a problem studied in spacecraft designs since the early days of large, liquid-fuel rockets. The conventional design solution involves physical…
(more)
▼ Propellant slosh has been a problem studied in spacecraft designs since the early days of large, liquid-fuel rockets. The conventional design solution involves physical
structures inside the fuel tanks that limit propellant motion. Although effective, baffles and bladders add to spacecraft mass and structural complexity. In this research, the sloshing fuel mass is treated as an unactuated degree of freedom within a rigid body. Specifically, the propellant is modeled as a pendulum mass anchored at the center of a spherical tank. After obtaining the coupled equations of motion, several linear controllers are developed to achieve planar spacecraft pitch-maneuvers while suppressing the slosh mode. The performance of these linear controllers will be compared to that of a nonlinear controller developed using Lyapunov’s Second Method. It is shown that the linear controllers are ill-equipped to achieve the desired spacecraft attitude and transverse velocity simultaneously, especially during aggressive pitch-maneuvers; while the Lyapunov controller is superior in this regard.
Advisors/Committee Members: Dr. Mahmut Reyhanoglu, Dr. Bereket Berhane, Dr. Michael Hickey.
Subjects/Keywords: Space Vehicles; Structures and Materials
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APA ·
Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Savella, P. A. (2005). Maneuvering Control of a Spacecraft with Propellant Sloshing. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/db-theses/178
Chicago Manual of Style (16th Edition):
Savella, Philip A. “Maneuvering Control of a Spacecraft with Propellant Sloshing.” 2005. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/db-theses/178.
MLA Handbook (7th Edition):
Savella, Philip A. “Maneuvering Control of a Spacecraft with Propellant Sloshing.” 2005. Web. 01 Mar 2021.
Vancouver:
Savella PA. Maneuvering Control of a Spacecraft with Propellant Sloshing. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 2005. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/db-theses/178.
Council of Science Editors:
Savella PA. Maneuvering Control of a Spacecraft with Propellant Sloshing. [Masters Thesis]. Embry-Riddle Aeronautical University; 2005. Available from: https://commons.erau.edu/db-theses/178

Embry-Riddle Aeronautical University
29.
Schmidt, Ryan C.
An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab.
Degree: MSin Aerospace Engineering, Aerospace Engineering, 2009, Embry-Riddle Aeronautical University
URL: https://commons.erau.edu/db-theses/182
► Present generations rely heavily on the use of petroleum as their primary means of transportation. As the cost of petroleum continues to escalate, the…
(more)
▼ Present generations rely heavily on the use of petroleum as their primary means of transportation. As the cost of petroleum continues to escalate, the need for lightweight
structures for vehicle applications becomes more evident. The ability to engineer
materials so that they possess desired application specific properties and characteristics has made tremendous progress in the past century. Consequently, the use of these composite
materials for aircraft weight reduction has been investigated for decades.
The aerospace industry often uses composite
materials to make a laminated composite structure where each constituent ply of the laminate has its own material properties. This anisotropic behavior of a fiber-reinforced laminate (FRL) is discussed methodically throughout this research. Moreover, the successful design of an FRL is dependent upon the accuracy of analyzing its structural limits. Therefore, the failure criteria used to specify an FRL's failure limits are significant.
Although useful formulaic methods have been developed for analyzing fiber-reinforced laminates, these calculations can be quite tedious when used in an iterative structural design process. Development of software that can conduct computer-aided laminate failure analysis can provide an indispensable tool for the design of fiber-reinforced laminate composites. Hence, this research focuses on the development of such software, CFA (Composite Failure Analysis). Even though fiber-reinforced laminate failure analysis is not a trivial topic, CFA was developed to provide a knowledgeable engineer with an intelligible software utensil for the design of fiber-reinforced laminates. Additionally, CFA's simplistic exploitation of Excel® and MatLab® make it an indispensable tool for engineering education instruction.
CFA exhibits an immense potential for the advancement of Embry-Riddle Aeronautical University's educational prowess in the field of composite
materials. With its ability to perform fiber-reinforced laminate failure analysis using the universal engineering software platforms of Excel® and MatLab®, CFA provides the university with a novel capability for future composite
materials research.
Advisors/Committee Members: Dr. Yi Zhao, Dr. Magdy Attia, Dr. Frank Radosta.
Subjects/Keywords: Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Schmidt, R. C. (2009). An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab. (Masters Thesis). Embry-Riddle Aeronautical University. Retrieved from https://commons.erau.edu/db-theses/182
Chicago Manual of Style (16th Edition):
Schmidt, Ryan C. “An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab.” 2009. Masters Thesis, Embry-Riddle Aeronautical University. Accessed March 01, 2021.
https://commons.erau.edu/db-theses/182.
MLA Handbook (7th Edition):
Schmidt, Ryan C. “An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab.” 2009. Web. 01 Mar 2021.
Vancouver:
Schmidt RC. An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab. [Internet] [Masters thesis]. Embry-Riddle Aeronautical University; 2009. [cited 2021 Mar 01].
Available from: https://commons.erau.edu/db-theses/182.
Council of Science Editors:
Schmidt RC. An Intelligible Software (CFA) Approach for Fiber-Reinforced Laminate Failure Analysis Including a Piecewise Representation of the Tsai-Wu Failure Criterion Using Excel and MatLab. [Masters Thesis]. Embry-Riddle Aeronautical University; 2009. Available from: https://commons.erau.edu/db-theses/182

University of Colorado
30.
Metts, Jonathan Glen.
Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption.
Degree: PhD, Aerospace Engineering Sciences, 2010, University of Colorado
URL: https://scholar.colorado.edu/asen_gradetds/10
► Water consumption for space suit thermal control is a limiting factor on long-term space exploration missions. A concept is proposed for an integrated, flexible…
(more)
▼ Water consumption for space suit thermal control is a limiting factor on long-term space exploration missions. A concept is proposed for an integrated, flexible suit radiator using infrared electrochromic
materials for modulated heat rejection from the suit. Properties of electrochromic
materials, the structure of electrochromic devices, and relevant heat transfer processes are presented as background information. Analytical methods are employed to bound theoretical performance and determine required emissivity ranges for lunar surface operations. Case studies are presented incorporating Apollo program and Advanced Walkback Test metabolic and environmental data to estimate sublimator water consumption and hypothetical water savings with the electrochromic radiator. Concepts are presented and analyzed for integrating an electrochromic radiator with existing and future space suit designs. A preliminary systems-level trade analysis is performed with the Equivalent System Mass metric used to compare this technology with the legacy sublimator and other extravehicular activity cooling technologies in development. Experimental objectives, procedures, and results are presented for both bench-top and thermal vacuum testing of electrochromic radiator
materials.
Advisors/Committee Members: David M Klaus, James A. Nabity, Brian Berland.
Subjects/Keywords: electrochromic; extravehicular; lunar; radiator; Aerospace Engineering; Structures and Materials
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APA ·
Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Metts, J. G. (2010). Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/asen_gradetds/10
Chicago Manual of Style (16th Edition):
Metts, Jonathan Glen. “Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption.” 2010. Doctoral Dissertation, University of Colorado. Accessed March 01, 2021.
https://scholar.colorado.edu/asen_gradetds/10.
MLA Handbook (7th Edition):
Metts, Jonathan Glen. “Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption.” 2010. Web. 01 Mar 2021.
Vancouver:
Metts JG. Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption. [Internet] [Doctoral dissertation]. University of Colorado; 2010. [cited 2021 Mar 01].
Available from: https://scholar.colorado.edu/asen_gradetds/10.
Council of Science Editors:
Metts JG. Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption. [Doctoral Dissertation]. University of Colorado; 2010. Available from: https://scholar.colorado.edu/asen_gradetds/10
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