Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2009. / Thesis Advisor(s): Kwon, Young W. "September 2009." Description based on title screen as viewed on 6 November 2009. Author(s) subject terms: Fluid-structure interaction, composite, carbon fiber composite, dynamic response, finite element. Includes bibliographical references (p. 95-96). Also available in print.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Ashok Srinivasan, Florida State University, Dept. of Computer Science. Title and description from dissertation home page (viewed Oct. 14, 2004). Includes bibliographical references.

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Peng Xiong, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains xvii, 119 pages. Includes bibliographical references.

Thesis (M.S.)--Florida State University, 2005. / Advisor: Zhiyong Liang, Florida State University, FAMU-FSU College of Engineering, Dept. of Industrial and Manufacturing Engineering. Title and description from dissertation home page (viewed Jan. 11, 2006). Document formatted into pages; contains xi, 112 pages. Includes bibliographical references.

Lightning damage resistance of unstitched carbon/epoxy laminates and a Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panel were characterized by laboratory-scale lightning strike tests and multiphysics-based lightning strike finite element (FE) models. This dissertation combines three related research topics: (1) a three-dimensional (3D) heat transfer problem, (2) lightning damage resistance assessments of carbon/epoxy laminates, and (3) lightning damage resistance of PRSEUS panel. The first project deals with a 3D analytical heat transfer problem as a solid foundation for understanding the steady-state temperature distribution in an anisotropic composite heat spreader. The second project characterizes lightning damage to unprotected carbon/epoxy laminates and laminates with either copper mesh (CM) or pitch carbon fiber paper (PCFP) protection layers subjected to standard impulse current waveforms, consistent with actual lightning waveforms, with 50, 125, and 200 kA nominal peak currents. Multiphysics-based FE models were developed to predict matrix thermal decomposition (a primary form of lightning damage) in unprotected, CM-protected, and PCFP-protected carbon/epoxy laminates. The predicted matrix decomposition domains in the damaged laminates showed good agreement with experimental results available in the literature. Both the CM and the PCFP lightning protection layers successfully mitigated lightning damage development in the underlying composites. The third project includes lightning damage characterization of a PRSEUS panel. Laboratory-scale lightning strike tests with nominal 50, 125, and 200 kA peak currents were performed at the mid-bay, stringer, frame, and frame/stringer intersection locations of the PRSEUS panel. The elliptical regions of intense local damage were elongated along the outermost lamina’s carbon fiber direction, consistent with observations from the unstitched carbon/epoxy laminates. However, the damaged PRSEUS panel exhibited unique damage features due to use of warp-knitted fabrics and through-thickness VectranTM stitches. The polyester threads used to weave the warp-knitted laminates locally confined small-scale fiber damage. This resulted in somewhat periodic and scattered small tufts of carbon fibers near the lightning attachments. Through-thickness VectranTM stitches also confined intense local damage development at the stringer and frame locations. The polyester warp-knit fabric skins and through-thickness VectranTMstitches have a significant beneficial effect on lightning damage development on a PRSEUS panel.

High temperature polyarylene networks produced through the step-growth thermal cyclopolymerization of mono-ortho-diynylarene (MODA) and bis-ortho-diynylarene (BODA) monomers have been shown to produce high yielding glassy carbon once pyrolyzed at 1000 °C. In this study the homo- and co-polymerization of both monomers will be studied, and the effects of copolymer composition on the processability when applied to carbonization and carbon-carbon composites. The carbon products from these high temperature polymer matrices will also be characterized. MODA and BODA are prepared through a Sonogashira coupling reaction and are polymerized through a heat-initiated Bergman Cyclization reaction mechanism. This work seeks to show how BODA-MODA copolymers can attenuate current composite processing limitations, and improve mechanical properties while retaining high temperature properties including high carbon yields.

In recent times, composite materials have gained mainstay acceptance as a structural material of choice due to their tailorability and improved thermal, specific strength/stiffness and durability performance. Carbon-Carbon (C/C) composites are used for high temperature applications such as exit nozzles for rockets, leading edges for missiles, nose cones, brake pads etc. Mechanical property estimation of C/C composites is challenging due to their highly heterogeneous microstructure. Computed Tomography (CT) images (volumetric imaging) coupled with Scanning Electron Microscopy (SEM) reveal a highly heterogeneous microstructure comprised of woven C-fibers, amorphous C-matrix, irregularly shaped voids, cracks and other inclusions. The images also disclose structural hierarchy of the C/C composite at different length scales. Predicting the mechanical behavior of such complex hierarchical materials like C/C composites forms the motivation for the present work. A systematic study to predict the effective mechanical properties of C/C Composite using numerical homogenization has been undertaken in this work. The Micro-Meso-Macro (MMM) principle of ensemble averages for estimating the effective properties of the composite has been adopted. The hierarchical length scales in C/C composites has been identified as micro (single fiber with matrix), meso (fabric) and macro (laminate). Numerical homogenization along with periodic boundary conditions (PBCs) have been used to estimate the effective engineering properties of the material at different length scales. Concurrently, mechanical testing has also been carried out at macro (compression tests) and micro scale (using nano-indentation studies) to characterize the mechanical behavior of C/C composites.

No description available.

Thesis (M.S.)--State University of New York at Binghamton, Department of Mechanical Engineering, 2006. / Includes bibliographical references.