IMPLEMENTATION OF A GENERALIZED MIDPOINT ALGORITHM FOR INTEGRATION OFELASTOPLASTIC CONSTITUTIVE RELATIONS FOR VONMISES HARDENING MATERIAL

This paper presents a detailed description of the computer implementat ion of a generalized midpoint algorithm for integration of constitutiv e relations for von Mises' hardening material. A nonlinear scalar equa tion for determination of the plastic multiplier is derived. The solut ion of this equation for a hardening material, by the Newton-Raphson m ethod, usually converges in three-four iterations. The results obtaine d by the generalized midpoint method for the hollow sphere under inter nal pressure are compared with analytical and converged subincrementat ion solutions. A pseudocode of the algorithm and a module in the C pro gramming language is given in the Appendix.