CREEP FRACTURE MODELING BY USE OF CONTINUUM DAMAGE VARIABLE BASED ON VORONOI SIMULATION OF GRAIN-BOUNDARY CAVITY

A new approach to creep cavitation damage is developed by combining th e basic features of continuum damage mechanics and mechanism-based cav itation models. Based on a polycrystal microstructures simulated by Vo ronoi tessellation, an anisotropic continuum damage variable is define d, and its evolution is given by applying the mechanism-based equation s of cavity nucleation and growth to each grain boundary. Macroscopic creep deformation coupled with the damage variable is calculated by da mage mechanics equations. The proposed method has been applied to inve stigate the damage evolution under uniaxial tension and reversed shear loading conditions. (C) 1997 Published by Elsevier Science Ltd.