Void growth yield criteria for intergranular ductile fracture

Ductile fracture through growth and coalescence of intergranular cavities is a failure mode observed experimentally in many metallic alloys used industrial applications. Simulation this process polycrystalline aggregates requires modeling the plastic yielding porous boundaries. However, classical yield criteria for materials such as Gurson–Tvergaard–Needleman model its current extensions cannot account complex coupling between loading state, crystallographic orientations, void shape material behavior at grain In order to bridge gap, two ductile are proposed. The first one GTN-like derived from limit-analysis which, once calibrated, accounts spherical voids interface rate-independent crystals. second developed variational approach predicts viscoplastic crystals containing ellipsoidal cavities. Both models validated against wide database numerical bi-crystals using FFT solver. Satisfying agreements obtained, paving way microstructure-informed simulation. interplay inside grains along boundaries finally studied based on proposed criteria.