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Thesis (M.S.)--Rochester Institute of Technology, 1991. / Typescript. References: leaves 139-147.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 138 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 90-94).

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007. / White, Donald, Committee Member ; Haj-Ali, Rami, Committee Chair ; Will, Kenneth, Committee Member.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed July 9, 2007). PDF text: 118 p. : ill. UMI publication number: AAT 3252834. Includes bibliographical references. Also available in microfilm and microfiche formats.

A complete solution of thermoelastic dilatational waves in an elastic, heat conducting, homogeneous, and isotropic medium has been obtained for both the steady and unsteady states. Discussions of the solution for a wide range of frequencies and various values of the coefficient of rise (or decay) have been made and the result has been applied to the explanation of the unusual seismic waves recorded from an underground atomic explosion of September 19, 1957, in Nevada. Reflection and retraction of plane waves at plane boundary and plane interface between two media have been studied. The surface waves have also been studied. The solutions of spherical and cylindrical dilatational waves have been found. / Ph. D.

A single piece of optical fiber can be utilized to sense both strain and temperature simultaneously. To develop such a sensor, we sandwich a section of two-mode elliptical core (e-core) fiber between two partially reflecting mirrors. This configuration can be considered as an intrinsic Fabry-Perot interferometer, in which the two-mode, e-core fiber serves as the resonant cavity. Two different types of phase modulation can be extracted under perturbations of strain and temperature on the fiber. These phase changes are due to the two-mode interference and intrinsic Fabry-Perot interference, respectively. The relationship between the phase information and the two physical measurands, i.e. strain and temperature, can be established using two coupled equations, in which the strain and temperature are considered as two unknowns. By solving these two coupled equations, we can simultaneously determine the strain and temperature. The waveguide theory and the Cross sensitivity analysis of this sensor are presented. The descriptions of four independent experiments that have been used to determine the coefficients of the two coupled equations are given. The resolutions of the strain and temperature measurements have been obtained to be 31 μm/m and 4.5 °C, respectively. / Master of Science

This study develops new quantitative thermoelastic stress analysis (TSA) techniques for fracture and fatigue damage analysis of composite materials. The first part deals with the thermo-mechanical derivation of two quantitative TSA techniques applied to orthotropic composites with and without a transversely-isotropic surface coating layer. The new TSA test procedures are derived in order to relate the thermal infrared (IR) images with the sum of in-plane strains multiplied by two newly defined material constants that can be experimentally pre-calibrated. Experiments are performed to verify the TSA methods with finite element (FE) numerical results along with available anisotropic elasticity solution. The second part of this study applies the quantitative TSA techniques together with the Lekhnitskii's general anisotropic elasticity solution to calculate mixed-mode stress intensity factors (SIFs) in cracked composite materials. The cracked composite coupons are subjected to off-axis loadings with respect to four different material angles in order to generate mixed-mode SIFs. A least-squares method is used to correlate the sum of in-plane strains from the elasticity solution with the measured TSA test results. The mode-I and mode-II SIFs are determined from eccentrically loaded single-edge-notch tension (ESE(T)) composite specimens. The FE models and virtual crack closure technique (VCCT) are utilized for comparisons. In the third part, a new stochastic model is proposed to generate S-N curves accounting for the variability of the fatigue process. This cumulative damage Markov chain model (MCM) requires a limited number of fatigue tests for calibrating the probability transition matrix (PTM) in the Markov chain model and mean fatigue cycles to failure from experiments. In order to construct the MCM stochastic S-N curve, an iterative procedure is required to predict the mean cycles to failure. Fatigue tests are conducted in this study to demonstrate the MCM method. Twenty-one open-hole S2-glass laminates are fatigue-cycled at two different stress levels. The coupon overall stiffness and surface-ply TSA damage area have been used as two damage metrics. The MCM can satisfactorily describe the overall fatigue damage evolution for a limited number of coupons (less than 6) subjected to a given specific stress level. The stochastic S-N curve can be constructed using at least two sets of fatigue tests under different stress levels. Three available fatigue tests for different E-glass laminates from the literature are also investigated using the proposed MCM approach. The results show the MCM method can provide the stochastic S-N curves for different composite systems and a wide range of fatigue cycles.

Bibliography: leaves 243-256. / xi, 258 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / In this thesis, time-independent thermoelastoplastic and time-dependent creep stress and damage analysis of thick-walled cylinders are investigated using incremental theory of plasticity in conjunction with improved material elastoplastic and creep constitutive models. The results are validated experimentally and numerically. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1996

Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Rami Haj-Ali; Committee Member: Arash Yavari; Committee Member: Bruce R. Ellingwood; Committee Member: Kenneth M. Will; Committee Member: Richard W. Neu.