A NOVEL SIN-HYPERBOLIC CREEP DAMAGE MODEL TO OVERCOME THE MESH DEPENDENCY OF CLASSIC LOCAL APPROACH KACHANOV-RABOTNOV MODEL

摘要

All materials include defects or voids. Under load, these defects can serve as a nucleus of crack initiation and propagation. Numerical analysis of notched specimen can provide prediction of creep damage or crack propagation of materials containing defects or initial cracks. However, FEM analyses using the local CDM approach exhibits mesh size dependency, and exhibits localized damaged zone around the crack. In this study, a novel Sin-hyperbolic (Sinh) model is demonstrated to significantly mitigate mesh dependency and exhibits a nonlocal damage distribution around the crack when compared to the classical Kachanov-Rabotnov model. Finite element analysis of circular notched specimen of 304 Stainless-Steel (SS) is performed. Contour plots of damage evolution, and mesh dependency of crack growth rate are discussed in detail. It is demonstrated that the Sinh model offers better creep damage, and crack growth analysis and significantly improves the stress sensitivity, damage localization, and mesh-dependency of numerical results.