Upper bound analysis of plastic limit loads on orthotropic structures

The aim of this paper is to calculate the plastic limit loads of structures made of orthotropic materials. The criterion yielded by Hill-Tsai was used to reduce the limit loads solution to a nonlinear programming problem using the upper bound analysis of plastic limit theory and the finite element method for the analysis of the plastic limit loads of orthotropic structure. The nonlinear theory of mathematical programming was used to develop a direct iterative algorithm for the above problem. Some examples are given to illustrate the validity of the method. The results show that the method can facilitate the design and application of orthotropic structures.