Methods of structural optimization have been studied and developed over the last three decades. An important aspect of structural optimization pertains to the conditions under which the loads are applied. Problems in which the applied load is single and deterministic are well documented in the literature, whereas those in which the load is deterministic but varying, stochastic, or uncertain have been less studied. Although methods of structural optimization under single-loading conditions can be extended to multiple-loading cases, the computational burden imposed by these methods is often extremely high, to the point of becoming inapplicable. / In this thesis, a novel approach is introduced. We first propose the use of the concept of stiffness ellipsoid, whose boundary defines the field of displacements of a structure subject to a load with a constant magnitude, but applied in an arbitrary direction. Based on the study of the stiffness ellipsoid, an optimality criterion that determines the worst case of the structure subject to a load with a given magnitude, but applied in an arbitrary direction, is proposed. The underlying ideas are applied to the structural optimization of the roller-carrying disk of a novel class of cam-follower speed-reduction devices---Speed-o-Cam (SoC). The optimum structures obtained in this thesis are compared with the existing prototype, which was designed using established design criteria only. Results indicate an improvement of almost twice the stiffness with a mass reduction of 40% of the original prototype. / Also reported in the thesis is a novel algorithm of mesh generation, named the contour mesh generation algorithm (CMGA). The CMGA, based on the concept of penalty functions, is applied throughout the examples given in the thesis and shows a great advantage in solving structural optimization problems.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.84440 |
| Date | January 2002 |
| Creators | Teng, Chin-Pun, 1971- |
| Contributors | Angeles, Jorge (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Mechanical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001985739, proquestno: AAINQ88587, Theses scanned by UMI/ProQuest. |
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