Mesoscopic Damage Model and Constitutive Model of Polymer Bonded Explosive Under Confined Impact Load

In order to obtain the meso-damage model and constitutive model of polymer bonded explosive under impact load, based on the first-level light gas gun, the confined impact damage experiment of PBX-JH14C was designed to obtain the stress history curves at different velocities. Scanning electron microscopy (SEM) was used to observe the microscopic morphology of the recovered samples. The results showed that the internal damage of PBX-JH14C under confined impact was mainly trans-granular fracture. The VUMAT was developed based on viscoelastic statistical crack model, and was inserted into ABAQUS to conduct numerical simulation of SHPB experiment. The validity of the model and parameters was verified by comparing the experimental results, and the confined impact test was further simulated to analyze the damage degree of PBX-JH14C at different speeds. The numerical simulation is in good agreement with the experimental results, indicating that the constitutive model can describe the mechanical properties of the explosive under different loading conditions, and the damage degree of PBX-JH14C increases with the increase of velocity.