Mechanical Property and Damage Evolution of Polymer-Bonded eXplosive Substitute under Biaxial Compression

Understanding both the mechanical property and the crack propagation behavior of Polymer-bonded eXplosive (PBX) material under biaxial compression is critical to predicting its safe working life. In this study, a number of PBX substitute specimens were tested under lateral confining pressures varying from 0 to 40MPa to better understand the mechanical behavior and damage evolution characteristics of PBX material under biaxial compression. The failure modes, ultimate strength and deformational behavior of PBX substitute under biaxial compression were observed using digital image correlation (DIC) method, and the damage of material was evaluated through the quantitative analysis of micro-computed tomography (CT) images of post-test specimens. The results indicate that the confining stress in the biaxial minor principal direction has a noticeable effect on the strength and deformational behavior of the PBX substitute material and the maximum increase of compressive strength occurs at a lateral confining pressure around 30MPa. The three-dimensional morphology of cracks was also examined quantitatively. The extent and complexity of crack damage were found increasing with the lateral confining pressure when it is smaller than 30MPa.