RATCHETING OF CYCLICALLY STABLE MATERIALS: II. IMPLICIT STRESS INTEGRATION ALGORITHM AND FINITE ELEMENT IMPLEMENTATION

The numerical calculation method and finite element implementation of a new visco-plastic constitutive model developed in the first part of this work are discussed. The model describes the ratcheting of cyclically stable materials reasonably. Based on the radial return method and backward Euler integration, a new implicit stress integration algorithm is proposed for the developed visco-plastic constitutive model by combining the successive substitution method. Meanwhile, in order to implement the model into a commercial finite element code(such as ABAQUS), a new expression of consistent tangent modulus necessary for whole nodal iteration of finite element calculation is also derived for rate-dependent plasticity. Numerical examples are given to verify the advantage of the stress integration algorithm and the finite element implementation, as well as the capability of the model in simulating the ratcheting of specific structural components.