Experimental and numerical simulation investigation on dynamic fracture behavior of polymer bonded explosives under different high-g impact conditions

Abstract

Impact tests of a projectile body penetrating a concrete target plate were carried out. In order to prolong the deformation stage without radial constraint of the PBX in the high-g impact environment and facilitate the study of the deformation and fracture of the PBX, the charging mode with a large gap was adopted. The different high-g environments of the PBX were realized by changing the weight of the steel pillar after the PBX. The mechanical response and damage failure modes of PBX with two different initial densities under different high-g impact conditions were investigated. Based on the viscoelastic-plastic constitutive model, a new constitutive model was developed by adding fracture. Then, the constitutive model established in this paper was used to simulate the impact tests in different deceleration environments using LS-DYNA large finite element software. By comparing with the experimental results, the results of the model were shown to be reliable and accurate. Through this model, the dynamic mechanical property curve and the fracture process of the PBX during the penetration process under high-g conditions, which could not be measured and observed in the test, were obtained. The crack propagation path and critical stress of the PBX under different high-g conditions were evaluated. The study is of great significance to analyze the dynamic failure mode of the PBX under high-g conditions.