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Thesis (Ph.D.)--University of Tulsa, 1994. / Includes bibliographical references (leaves 203-210).

Thesis (M.Sc.) - Dept. of Applied Mathematics, University of Adelaide, 1984. / Typescript (photocopy).

Thesis (M.E.)--University of Adelaide, Dept. of Civil Engineering, 1973.

Thesis (Ph.D) --University of Edinburgh, 1994.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xiv, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 111-113).

This thesis aims to model the effects of interaction and buckling upon pairs of micro-shells embedded within an elastic medium under far field hydrostatic pressure. This analysis is motivated by the role shell buckling plays in the nonlinear nature of the pressure relative volume curve of elastomers containing micro-shells. Current models of the effective properties of these types of composites assume shells are in a dilute distribution within the host medium, and as such assume shells will buckle at the pressure of the associated isolated embedded shell model. For composites with a high volume fraction of micro-shells, or in poorly mixed composites, the dilute distribution model may provide a first approximation to the effective properties of the composite, however, interaction between shells must be considered to find a more accurate model. We begin the process of modelling the buckling of interacting embedded shells by considering the buckling of an isolated embedded thin spherical shell. For a host medium undergoing far field hydrostatic pressure we demonstrate the parameter ranges in which Jones et al. thin shell buckling theory agrees with the thin shell buckling theory of Fok and Allwright. We then use scalings to increase the range of validity of the thin shell approximation used in the Jones et al. theory to include composites with a high contrast between medium and shell materials. This enables more accurate predictions of buckling pressures of embedded shells under far field axially symmetric pressures to also be found, as is demonstrated for an embedded shell under far field axial compression. We model the linear elastic deformation of pairs of embedded micro-shells using the Boussinesq-Papkovich stress function method, before employing the thin shell linear analysis method developed in previous chapters to calculate the critical buckling pressure and buckling patterns of the pair of embedded shells.

This thesis presents the results of a theoretical and experimental study of the lateral buckling of two- and three-hinged arches of rectangular cross-section with laterally restrained top edges. The structure is analysed with and without a linear torsional restraint along the top edge. The problem is formulated using the stiffness method. A stiffness matrix including the effects of lateral bending and torsion is used. The buckling load is defined as the smallest load at which the structure stiffness matrix becomes singular. The method of solution of the theoretical lateral buckling is iteration (eigen value problem) and determinant plot. This theoretical approach is verified by model tests with two- and three-hinged parabolic glulam arches in the laboratory. The method of solution for model test is the Southwell plot. The results of the tests are presented and are shown to be satisfactory. A set of numerical results are given for a range of arches with torsional restraint at the top edge and for various load distributions. A sample of calculations of a practical arch shows that, although the arch is safe according to the existing code, it is only safe considering lateral buckling including a torsional restraint at the top edge. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The lateral buckling of two hinged glulam parabolic arches of rectangular cross-section with laterally restrained top edges is investigated. The problem is formulated using the stiffness method. The structure is idealised as a series of straight segments. A stiffness matrix including the effects of lateral bending and torsion is derived and it is shown how the structure stiffness matrix is generated. The buckling load is defined as the smallest load at which the structure stiffness matrix becomes singular. Three methods of solution are given; iteration, determinant plot and Southwell plot. Experimental tests were carried out to check the validity of the theory. The results of the tests are presented and are shown to be satisfactory. A set of numerical results are given for a range of arches and load distributions and a set of design parameters are proposed. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate