Rate-dependent plasticity and bond-level damage model in ordinary state-based peridynamics

This study develops a general rate-dependent plasticity and damage framework within the ordinary state-based peridynamic (OSB-PD) formulation for modeling dynamic failure of metals. A rate-dependent plasticity model grounded in J2 plasticity theory is first constructed to provide a unified description of strain hardening, strainrate sensitivity, and thermal softening. On this basis, a progressive bond-level damage model (BLDM) is introduced to replace the node-level damage model (NLDM), overcoming issues such as nonphysical crack widths, excessive material point spattering, and poor convergence. Within this general framework, the Johnson-Cook (JC) constitutive law is incorporated due to its ability to describe the rate and temperature effects on metal. The proposed framework accurately reproduces uniaxial tension responses of metallic materials, including elastic deformation, strain hardening, damage accumulation, necking, and fracture. The predicted stress-strain curves and fracture strains agree well with experiments across a wide range of strain rates and temperatures. Benchmark simulations further demonstrate the capability of the framework: the Charpy impact test captures tensile fracture with accurate force-displacement response, the Kalthoff-Winkler test reproduces the shear-to-tensile failure transition, and plate penetration simulations recover petaling fracture patterns. Overall, the BLDM framework provides a robust tool for simulating dynamic metal fracture, with strong potential for applications in impact and explosion problems.