Pattern Transformation Method for Shape Optimization and its Application to Spoked Rotary Disks

Abstract : A technique to determine effectively an uniformly stressed shape of two-dimensional design bodies under body force, which has been suggested already by the authors and is so-called Pattern Transformation method, will be explained plainly. This technique is one of the stress-ratio methods and based on an iterative method consisting of the following steps. In the first step, the deviation of a given shape from the design object is judged by the comparison with the stress at each point on the boundary and the design objective stress. In the next step, the given shape is modified to approach that to an optimum shape by the proportional transformation of the finite elements constituting the boundary. By applying this technique the optimum strength shapes of the rotating disks with some spokes such as the flywheel, the belt wheel and the gear of large diameter are obtained. Furthermore the validity of the obtained shape is examined experimentally by the spinning fracture test. (Author)