Application of continuum damage model to life prediction of geometrically nonlinear structure in high temperature

In this investigation, the basic concept of continuum damage mechanics was described and the thermodynamic approach to derive the viscoplastic constitutive equations and the consistent method of introducing the damage variable into the viscoplastic constitutive equations are discussed. General viscoplastic constitutive laws with several state variables have been implemented in the general-purpose finite element code ABAQUS to predict the viscoplastic response of the structure subjected to a cyclic loading. The safety assessment for a geometrically nonlinear high temperature structure subjected to severe transient thermal and mechanical loading was carried out. Chaboche's viscoplastic model was adopted to describe the material behavior of 316 stainless steel at high temperature and modified to introduce the internal damage. The damage contour of the structure was illustrated and the efficiency of the proposed procedure was discussed