PLASTICITY AND DAMAGE KELVIN MODES BASED MODEL FOR SINGLE CRYSTAL SUPERALLOYS

摘要

A new plasticity and damage model based on Kelvin modes is formulated here for FCC nickel-base single crystals materials. Indeed, relying on the cubic symmetry of these alloys, the Kelvin decomposition of elasticity tensor allows for the non quadratic proposal of an objective and loading independent criterion. The criterion identification is performed from different loading cases for CMSX2 single crystal superalloy. The results show that a simple three-parameter yield criterion built thanks to two von Mises equivalent Kelvin stresses accounts for a satisfying plasticity criterion for such alloys. Moreover this yield criterion is naturally a basis to build a complete plasticity model including isotropic and kinematic hardenings. Full coupling with anisotropic damage is gained thanks to effective Kelvin stresses.