IMPLICIT DAMPING ITERATION ALGORITHM FOR ELASTOPLASTIC EQUATIONS

Authors present an integral weak form of elastoplastic problem for simultaneously solving equilibrium equations, yield function, and plastic flow equations, and two algorithms for displacement increment iteration: 1) iteration algorithm based on independent unknowns of strain increment and plastic factor; 2) numerical solution based on the only unknowns of strain increment. An implicit damping iteration algorithm is proposed to avoid singularity of elastoplastic matrix and improve convergence speed. Script codes are designed for the iteration process, and finite element programs are generated based on Finite Element Program Generator (FEPG). The programs are verified and computational results agree well with theoretical solutions.