Shape modification of structures composed of curved plates for the reduction in stress concentration.

Abstract

As a basic study for computer-aided machine design, an interactive shape modification method and a computer program to reduce stress concentration factors for three-dimensional structures composed of curved plates are developed in this report. This method consists of two parts, automated stress analysis and interactive shape modification. Automated stress analysis consists of automated mesh generation and stress analysis. The stress analysis is based on the Assumed Stress Hybrid Method and the Gaussian Elimination Method. Shape modification is classified into three types, inter-plate modification, elliptical modification and thickness modification. Inter-plate modification is the modification of shapes near the intersection lines between two curved plates. Elliptical modification is the modification of shapes of plates such as end closureof a pressure vessel. Thickness modification is modification of the thickness of plates near the intersection lines. The usefulness of the program is illustrated with the help of several examples of practical interest.