SECANT STRUCTURAL SOLUTION STRATEGIES UNDER ELEMENT CONSTRAINT FOR INCREMENTAL DAMAGE

Two major difficulties in the nonlinear analysis of post-peak structural behavior are the occurrence of an ill-conditioned tangent stiffness matrix around critical points, namely limit and bifurcation points, and the selection of a suitable constraint on the solution path. As an attempt to make failure prediction available in a routine manner, new solution strategies are proposed in which a secant structural stiffness matrix is formulated for incremental damage models, and the solution path is controlled through a suitable measure of failure at the most severely damaged point in the body. Numerical solutions are given for plane strain and plane stress problems to show that snap-back and snap-through associated with shear band formation can be inexpensively predicted.