Thesis (Ph. D.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed February 12, 2008) Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2007. / Includes bibliographical references (p. 119-122).

Thesis (Ph. D.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 229-245.

Previously published as first author's thesis (Ph. D. in Engineering--University of California, Berkeley, 2004). / "June 2005." Includes bibliographical references. Also available as an electronic document from the Earthquake Engineering Online Archive Earthquake: http://nisee.berkeley.edu/elibrary.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 334-340).

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

The purpose of this study is to develop a simple one-dimensional model to analyze axially loaded beam-plates containing cracks which extend through the thickness of the beam-plates. Although the material analyzed is isotropic, these cracks will be referred to as delaminations. Buckling, postbuckling, and growth of delaminations in these beam-plates will be analyzed. A finite element method in which all of the terms of the stiffness matrices are obtained by exact integration is employed to determine the linear buckling load and postbuckling solution. The energy release rate is then determined using the postbuckling solution. Curves are provided to show the effect of delamination length and location on buckling loads, energy release rates, and strengths of the beam-plates. The problem of buckling and postbuckling of beams with multiple delaminations is also considered. A method of calculating the energy release rate for beams with multiple delaminations using numerical differentiation is introduced. / Master of Science

In the assumptions, it was indicated that a modification in the method of analysis would allow taking into account the variation in pressure. This could be done by assuming that the internal pressure P used in the analysis was the pressure after deformation. During deformation, the mass of the enclosed gas remains constant. Thus, knowing the initial and final volumes and the final pressure, the initial internal pressure could be determined using the appropriate gas law. / Master of Science

Three models are presented which predict frequencies and mode shapes of transverse vibration for a continuous prismatic Bernoulli-Euler beam on elastic supports, subjected to a compressive axial load. The first model, which approximates support stiffnesses by an equivalent elastic foundation, is found to be inaccurate for wave lengths close to the support spacing. A discrete mass model is formulated which accounts for axial load by stability functions which modify the element stiffness matrices. A continuous model is formulated which yields an exact solution for Bernoulli-Euler beam theory. The frequencies predicted by the discrete mass model and continuous model are in excellent agreement. A method of predicting axial compressive load and support stiffness based on measured frequency and phase data is presented which can be used for either the discrete mass model or the continuous model. A frequency reduction factor is derived which accounts for the effects of shear deformation and rotatory inertia. Tests are performed on an eight span beam with compressive axial load. Test results show that the models accurately predict frequencies and mode shapes of vibration. Results indicate that the method formulated can be used to determine compressive axial load and support stiffness. / Master of Science

Inflated fabric is being considered as new structural material at the present time. It can be used in certain applications with the advantage of reducing the weight of structures, it is adaptable as an architectural element of construction; moreover, it may be developed to be one of the most economical, and simple structural materials in the future. A number of experimental investigations of these inflated fabric structures has been studied by research units of airship and fabric companies. However, due to the difficulties of solving such problems by analysis, there is still lack of theoretical methods, even approximate solutions. The purpose of this thesis is to investigate theoretical analysis for finding the relation between the applied load and the deflections, stresses, and also the end shortening of an inflated cylindrical fabric envelope subjected to axial compression, by the energy method. A cylindrical shape is selected because sphere and cylinder are considered more general in use and more easily to be treated than any other geometrical shapes. Also, for the sake of simplicity, a constant internal pressure is assumed in the analysis. The use or large deflection theory for finding the critical buckling loading of thin shells was first advanced by Von Karman and Tsien (reference 6 and 7). Based on their conception; numerous studies concerning the buckling strength under various loadings have been investigated by others subsequently. The strain-displacement relation in their papers is expressed in the following form including terms up to second order: ε_x= ∂u/∂x+(½)(∂w/∂x)² ε_x= ∂v/∂y+(½)(∂w/∂y)²-(w/R) In this thesis, although the idea is applied to develop an analysis by the energy method, the strain-displacement relation is expressed in a different way which will be shown in the following sections. Generally, in avoiding the mathematical difficulty of solving the differential equations obtained from the energy expression, most boundary-value problems in the theory of elasticity may be solved by assuming a solution in the form of a series which satisfies the boundary conditions, then minimizing the energy expression to determine the values of unknown parameters in the assumed solution. In this thesis, instead of using the variational method mentioned above, a graphical method for solving the differential equations is presented. However, owing to the fact that not all of the boundary conditions are specified at one point, the final results have to be obtained. by trial and error. / Master of Science