Numerical Analyses of Dynamic Crack Propagation in Visco-Plastic Solids Using Path Independent Integral, T

This paper presents the numerical analyses of dynamic crack propagation in visco-plastic solids. A tangent modulus formulation based on σ_yd=h(∊_up, ∊_up) is used to take into account visco-plasticity A linear relaxation technique of nodal forces is also employed for the modeling ot continuous dynamic crack propagation. The fracture mechanics parameter calculated here is a path independent integral, T^∗, which is applicable to both quasi-static and dynamic fracture phenomena of non-linear materials. First, a parametric calculation of dynamic crack propagation at a constant velocity in a visco-plastic solid is performed to investigate the high-strain-rate effects on the 1 integral and the stress-strain fields near the crack tip. Secondly, a generation phase calculation of an experiment performed by Brickstad is carried out to obtain a relationship between a fracture toughness and a crack velocity.