A Two Dimensional Rule-Based Shape Synthesis Method

Abstract

Abstract The objective of this study is to form two-dimensional structural/mechanical parts under general loading and restraint conditions. The designs created are of minimum weight with the stresses throughout the parts as close to the allowable limit as possible. The study uses a thresholding approach with minimal designer intervention for generating optimal configurations. The process begins with the user creating an initial design which encompasses all the specified loads and restraints. Finite element techniques are employed to discretize the part geometry. Then a set of heuristics are utilized for shape modification, by removing elements from the finite element model. A Bi-Directional Thresholding technique, BDT, is developed that determines which elements ought to be removed. After BDT is performed element connectivity is checked and maintained. A two-step connectivity check algorithm is implemented which locates and resolves major (complete) as well as minor (partial) losses in connectivity. This procedure, unlike most common shape optimization methods, is capable of quickly making very large changes in the geometry of the part. It is able to create holes in the geometry, where none existed in the initial shape, in order to produce a better design.