Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 111-114). Also available via the Internet.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 130-136). Also available via the Internet.

Thesis (M.S.)--University of Wisconsin-Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 32-34).

The optimal design of a plywood-web beam, as for any structural element, is usually found by trial and error in which an initial design is modified until a solution which maximizes the beam's efficiency and meets a set of prescribed design criteria is found. To automate this process, a reliability-based optimization program which computes the optimal dimensions of a plywood-web beam is formulated and tested in this study. The program minimizes the cost of a plywood-web beam subject to constraints imposed upon its performance expressed in terms of acceptable levels of safety with respect to a set of limit states. A plywood-web beam model which incorporates the effects of shear deformations in the web components and the effects of non-rigid connections between the beam's flanges and webs is developed and used to compute a plywood-web beam's response under load. The beam's performance is evaluated by means of a reliability analysis in order to rationally account for any uncertainty associated with the beam's material properties and the loads acting on it. An existing non-linear optimization routine computes the optimal continuous design of a plywood-web beam using the results of the structural and reliability analyses. A discrete solution, representing the optimal practical design which uses only available or allowable dimensions for the beam's components, is found by means of an exhaustive search of a restricted region of the design variable space near the optimal continuous solution. As an example, the program is used to optimize the design of a ply wood-web box girder. Sensitivity analyses are performed on the optimal design in order to identify and quantify the critical input parameters in the optimization process. The effects of errors in the problem's formulation, analytical errors arising from the structural analysis and statistical errors resulting in an inaccurate representation of the problem's probabilistic characteristics are studied. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Thesis (M.A.)--University of Delaware, 2007. / Principal faculty advisor: Bernard L. Herman, Dept. of Art History. Includes bibliographical references.

Thesis (M.S.)--Ohio University, March, 1997. / Title from PDF t.p.

This thesis consists of two parts. The first part describes the analysis and implementation of a finite element computer model for the general prediction of failure of wood members in bending or in combined bending and axial compression. Both instability and material strength failures are included. The program is verified using available analytical and test results. A good agreement with the results predicted by this program is observed. The second part describes a procedure for the structural reliability evaluation of a compression member assuming random loads and material variables. The program developed here for the reliability study links the finite element program and the Rackwitz-Fiessler algorithm for the calculation of the reliability index β. The gradient of the failure function, which is a necessary input to the Rackwitz-Fiessler algorithm, is computed numerically using the finite element routine. The results of the reliability study for a typical column problem are compared against the available results obtained by following the code procedures [as outlined in CAN3-086.1-M84 (1984)] for different slenderness ratios. A performance factor ɸ⍴ = 0.75, for compression members of any length is recommended in order to obtain a more accurate and consistent level of reliability in the design process. It is estimated that if this factor ɸ⍴ = 0.75 adopted in the current design practices, a level reliability index of the order of 4.0 can be achieved. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

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