Multiphysics non-ordinary state-based peridynamics for modeling non-shock ignition of PBX

Abstract

This paper presents a mechanical-thermal-chemical coupled multiphysics non-ordinary state-based peridynamics (NOSBPD) computational framework for investigating the non-shock ignition behavior of polymer-bonded explosives (PBXs). To combine the rate-dependent Johnson-Cook plastic constitutive model and the Arrhenius chemical reaction heat release model with nonlocal peridynamic enables the rigorous modeling of non-shock ignition behaviors of PBX charge, overcoming the challenges faced by the existing simulation techniques. Within such framework, a series of complicated processes such as dynamic deformation and fracture, crack nucleation and propagation, friction between crack surfaces, plastic dissipation, heat conduction, and crystal chemical reaction can be simulated in a simultaneous manner. The proposed approach is validated through classic examples including Kalthoff-Winkler (KW) impact and Taylor-bar impact tests. The predictive capability of the proposed approach is further demonstrated by modeling of the Steven test of PBX. The simulation results exhibit good agreement with both previous experimental and numerical results with respect to temperature evolution, pressure history, as well as critical impact velocity for ignition. In addition, the influences of impact velocities, explosive thicknesses, and projectile shapes on the ignition response of the PBX were analyzed, providing a deep and thoughtful understanding of ignition behaviors of PBX. The proposed multiphysics computational framework advances the development of non-shock ignition models and also can be utilized to guide the design of PBXs charges.