AN ACCELERATION METHOD IN ELASTOPLASTIC FINITE-ELEMENT COMPUTATION

In this work, an incremental iterative procedure will be adopted for the analysis of structural problems with elasto-plastic material behavior. The algorithm will concern a relaxation of the response increments obtained by the modified Newton-Raphson scheme. The relaxation parameters are defined by using the secant relation. This accelerating procedure can improve the convergence rate of the modified Newton-Raphson iteration significantly. This algorithm is very stable, even if large load sizes are adopted for the analysis. It is especially effective for consistently capturing the collapse load of a structure model without losing the control of computational efforts. The resulting algorithm is implemented into a finite element analysis computer code, and its performance is approved by numerical convergence tests. The application of this computational procedure is also extended to an analysis of crack propagation problems considering elasto-plastic material behavior.