NON-ORDINARY STATE-BASED PERIDYNAMIC THERMAL-VISCOPLASTIC MODEL AND ITS APPLICATION

A three-dimensional non-local thermo-visco-plastic solid model considering the strain rate effect, plastic hardening, thermal softening and fracture characteristics of materials, together with corresponding non-local spatial integral-type numerical method, have been proposed under the configuration of the recently developed non-ordinary state-based peridynamic (NOSB-PD) theory, and the model and numerical method have been employed to analyze the high-rate thermal-viscoplastic deformation and failure behavior of metallic materials and components under impact loads. The validity of the proposed model and algorithms was established through simulating the three-dimensional classical Kalthoff-Winkler impact experiment and comparing the numerical results including the cracking initiation time and orientation, crack propagation path and propagation speed, and the distribution of temperature and equivalent stresses in the target with experimental observations and available numerical results in literature. The proposed model and method were further applied to simulate the deformation and failure mechanism of double-notched metallic plates subjected to impact loads with different impacting velocities. Numerical results show that the present model inherits the advantages of both peridynamics and classical thermo-visco-plastic models, and is able to describe the whole elastic and plastic deformation and crack propagation processes qualitatively as well as quantitatively. Moreover, the effect of impact velocity on crack initiation time, crack propagation path and crack propagation speed were investigated. When subjected to impact load with lower impacting velocity, the crack initiation time of the target plate will be later (until no crack propagation appears when impacting velocity is lower than some value), and both the crack propagation speed and the peak temperature in the target plate will decrease.