A general algorithm for plastic flow simulation by finite element limit analysis

Limit analysis has been rendered versatile in many structural and metal forming problems[ In metal forming analysis\ the slip!line method and the upper bound method have _lled the role of limit analysis[ As a breakthrough of the previous work\ a computational approach to limit solutions is considered as the most challenging area[ In the present work\ a general algorithm for limit solutions of plastic ~ow is developed with the use of _nite element limit analysis[ The algorithm deals with a generalized Ho lder inequality\ a duality theoremand combined smoothing and successive approximation in addition to a general procedure for _nite element analysis[ The algorithm is robust such that from any initial trial solution\ the _rst iteration falls into a convex set which contains the exact solution"s# of the problem[ The idea of the algorithm for limit solutions is extended from rigid:perfectly plastic materials to work!hardening materials by the nature of the limit formulation\ which is also robust with numerically stable convergence and highly e.cient computing time