Numerical simulation of the effect of embedded gap on impact initiation of explosive PBX-9502

Aiming at the influence of the embedded gap on the impact initiation of the flat flyer of PBX-9502, the finite element simulation software LS-DYNA and the I-G model are used to establish the numerical calculation model of the cylindrical PBX-9502 with the embedded gap for the impact initiation of flat flyer, and analyze the influence of different impedance. The effect of the thickness and position of the large impedance gap on the reduction of the flyer initiation threshold is studied, the initiation velocity thresholds under different conditions are obtained, and the causes of abnormal detonation at the threshold velocity are analyzed. The results show that, under certain conditions, the small impedance gap will increase the impact initiation velocity threshold while the large impedance gap will decrease; the reduction effect of the position and thickness of the large impedance gap on the detonation velocity increased first and then decreased; both embedded gaps and deformed flying plates will produce Irregular reflection waves that affect the explosive initiated at a critical speed.