A Variable Load Step Solution Approach for Incremental Tangent Modulus Finite Element Analysis

摘要

This paper addresses the issue of load path discretization in incremental tangent modulus finite element analysis. The view is taken that discretization can best be accomplished during the course of the numerical solution by employing a constraint condition which restricts the level of structural stiffness approximation at each load step. By identifying a field variable which strongly influences the stiffness, a suitable constraint condition can be selected in terms of the nodal variables. With such a constraint, design of a solution algorithm for determining the step size along with the nodal variables is straightforward, as is demonstrated in the text. This variable load step solution approach provides the analyst with a simple yet efficient method for logically controlling step size, without having to resort to time consuming and costly reanalysis procedures to insure that the numerical approximation is within satisfactory tolerance. (Author)