Elastic-Plastic Analysis by Quadratic Programming

Antone F. Sayegh, Moshe F. Rubinstein

Journal of the Engineering Mechanics Division · 1972 · 10 citations · 0 references

Concepts

Abstract

The plastic principles of absolute minimum of the rate of total potential energy and total complementary potential are used as tools for fomulating the elastic-plastic analysis of various types of structures as a problem in nonlinear programming. The finite element technique is used to discretize a continuum and thus obtain an admissible field in terms of a finite number of parameters. For an elastic-perfectly plastic material it is shown that a force formulation has a definite advantage in that the knowledge whether a plastic element unloads or remains plastic becomes unnecessary and the problem can be formulated as a quadratic programming problem. Numerical examples illustrate the solution technique.