Abstract
A new and powerful material nonlinear analysis method for rigid plane frames is proposed on the basis of the principle of minimum complementary energy and mathematical programming algorithms. The analysis problem is formulated as the total complementary energy minimization problem subjected to the equilibrium equations at the free nodes in terms of the unknown forces acting at the ends of member elements. The unknown member end forces are determined by solving the energy minimization problem using a modified sequential quadratic programming algorithm.
The problem formulation and analysis algorithm of the proposed method are applicable for rigid frame structures with any types of nonlinear materials. The power, reliability, efficiency and practical usefulness of the method presented are demonstrated by comparing the results obtained with ones by the displacement method of analysis for several statically indeterminate rigid frame structures with three types of nonlinear materials
