A numerical study of intergranular fracture and oxygen embattlement in an elastic-viscoplastic solid

摘要

We present results from a numerical investigation of fracture along an embroiled surface embedded in an elastic-viscoplastic solid, an idealized model for high-temperature intergranular fracture in nickel-base superalloys. The formulation includes coupled models for the mechanical response, stress-assisted diffusion of oxygen, and a moving cohesive interface that determines crack initiation, growth and arrest. The entire system is formulated in a frame that translates with the crack tip and is implemented in an adaptive, space-time finite element code that supports both transient and direct steady-state calculations.