On the tension-induced microcracks' nucleation in a PBX substitute material under impact compression loading

摘要

Highlights?A PBX substitute material, i.e., polymer-bonded sugar material is designed.?PBS possesses the capability to adjust its microstructure.?The capability exponentially decays with strain rate.?The microcrack's nucleation is induced by tensile stress at the surface of defects.AbstractNucleation and growth of microcracks is a dominant form of damage evolution in polymer bonded explosives (PBXs). The mechanism of such a damage evolution of PBX under impact loading was analyzed in this study. For safety and convenience, a PBX substitute material was firstly designed by mixing sugar and a new agglomerant to form polymer-bonded sugar materials (PBS). The dynamic test was carried out by SHPB technique at different impact velocity. The cracks' nucleation of PBS was analyzed by means of Micromechanics. The results indicate that the material possesses capability to adjust its microstructure, and the dynamic tensile stress at the surface of defects induces the microcracks' nucleation.Graphical abstractIt was found at different strain rate that stress suddenly drops just after reaching peak value (from point 2 to point 3 in a stress-time curve), and then increases again (from point 3 to point 4).Display Omitted]]>