A reformulated non-ordinary state-based peridynamic method for dynamic failure of ductile materials

Abstract

A non-local correspondence peridynamic model is reformulated to describe the dynamic failure of ductile materials, under the framework of non-ordinary state-based peridynamics. To eliminate the zero-energy mode as well as to improve the numerical stability, the deformation gradient is updated on the bond level, which owns information including both the non-local deformation and the bond deviation. Peridynamic thermo-viscoplastic constitutive formulations are presented for the failure analyses of ductile materials. Moreover, a mixed strain-stress criterion describing the bond breaking and considering the temperature effect is presented on the bond level, in which the bonds can keep intact in calculations. Several comprehensive cases, including a notched tension test and Kalthoff-Winkler impact tests with different velocities, are investigated to verify the applicability of the proposed model for ductile fracture and impact failure. Numerical results, in terms of failure patterns, cracking switching and propagation, as well as adiabatic shear band propagation, show a reasonable agreement with corresponding experimental observations.