Numerical simulation of dynamic brazilian test of polymer bonded explosive simulant based on cohesive crack model

Polymer bonded explosive (PBX) is the key component of warhead. The dynamic behaviors of PBX, especially dynamic fracture behavior, are crucial issues on the safety and reliability of warhead. By introducing cohesive crack model (CCM), the dynamic explicit software LS-DYNA is used to simulate the dynamic Brazilian experiment on polymer bonded explosive simulant (PBX-M). By comparing with time history of tensile stress obtained by the strain gauge glued on the Hopkinson bar, the displacement fields and strain fields obtained by digital image correlation and high-speed camera, it is found that the tensile stress peak value obtained by numerical simulation is 5% smaller than the experimental result, and the deviation of the concentration zone of tensile strain from experimental data is less than 15%. Thus the validity of CCM is confirmed. The law of crack initiation and propagation of PBX-M sample during dynamic Brazilian experiment is studied from the results of numerical simulation. The quantitative information about crack width in sample is given.