FINITE ELEMENT IMPLEMENTATION OF ADVANCED CONSTITUTIVEMODEL EMPHASIZING ON RATCHETING

摘要

Two visco-plastic constitutive models for simulating cyclic deformation of cyclic stable and cyclichardening materials, respectively, were implemented into finite element code. The existed constitutive modelswere first extended to simulate the ratcheting and cyclic stress relaxation of the materials more reasonably byintroducing a combined kinematic hardening model. In finite element implementation, new nonlinear scalarequations of implicit stress integration algorithm and new expressions of consistent tangent modulus matrix for thetwo discussed models were formulated by using radial return method and backward Euler integration schedule.Some numerical examples are given to verify the advantage of the implementation and the capability of the modelsin simulating the ratcheting, cyclic stress relaxation, and strain cyclic behavior of the materials and structurecomponents.