Identification of Gurson's Material Constants and Estimation of Ductile Fracture at Interface Crack

The influence of parameters in the Gurson's constitutive equation for porous plastic materials on ductile fracture at an interface crack under mixed mode loading is discussed based on a comparison of computational and experimental results. A simple method to estimate the parameters using the deformation data of tensile specimens and the Kalman filter is proposed. A finite element simulation is performed to demonstrate the usefulness of the proposal method. It is suggested that two different specimens (e.g., one is a rectangular plate with a center hole and the other is a side notched plate) are necessary to guarantee a correct estimation.