Numerical studies on explosive welding with ANFO by using a density adaptive SPH method

Explosive welding (EXW) involves processes like the detonation of explosive charge, impact of metal structures and strong fluid-structure interaction with complex features. The EXW has not been well modeled before since in most numerical simulations the EXW is simply treated as the impact of two plates at high velocities. Recently, the authors developed a density adaptive smoothed particle hydrodynamics (SPH) method to successfully model the whole EXW process considering the high explosive explosion and its driving effects on flyer plate [1]. Later, this model is applied to investigate the mechanisms in EXW such as the wave formation mechanism and weldability windows [2]. The explosive TNT used in the previous model can be regarded as an ideal explosive while the complex and non-ideal explosive ANFO is more frequently used in practical welding operations. In this paper, the JWL + + model is incorporated into the density adaptive SPH to simulate the detonation of ANFO. The slab detonation and the explosive welding with TNT or ANFO explosive are simulated using the developed models. Good agreement can be observed between computational results and analytical solutions or experimental observations. Some typical characteristics in TNT and ANFO EXW including the detonation of explosive, wavy interface, jet formation, weldability windows are comparatively studied.