Damage localization of conventional creep damage models and proposition of a new model for creep damage analysis

Abstract

After examining the ill-natured stress sensitivity of the conventional creep damage equations of Kachanov-Rabotnov, it was shown that this stress sensitivity is one of the most essential causes of damage localization and mesh-dependence in local approach of creep fracture analyses. Then, in order to avoid this difficulty, alternative constitutive and evolution equations of creep and creep-damage are proposed from the view point of micromechanics. Finally, the proposed equations of creep and creep-damage are applied to the creep crack growth analysis of a perforated plate under tension. Significant improvement in damage localization and the mesh-dependence of the numerical results are ascertained.