Computational Investigation of Crack-Induced Hot-Spot Generation in Energetic Composites

Abstract

The sensitivity of polymer-bonded explosives (PBXs) can be tuned through adjusting binder material and its volume fraction, crystal composition and morphology. To obtain a better understanding of the correlation between grain-level failure and hot-spot generation in this kind of energetic composites as they undergo mechanical and thermal processes subsequent to impact, a recently developed interfacial cohesive zone model (ICZM) was used to study the dynamic response of polymer-bonded explosives. The ICZM can capture the contributions of deformation and fracture of the binder phase as well as interfacial debonding and subsequent friction on hot-spot generation. In this study, a two-dimensional (2D) finite element (FE) computational model of energetic composite was developed. The proposed computational model has been applied to simulate hot-spot generation in polymer-bonded explosives with different grain volume fraction under dynamic loading. Our simulation showed that the increase of binder phase material volume fraction will decrease the local heat generation, resulting in a lower temperature in the specimen.

Computational Investigation of the Mechanical Behavior of a Bone-Inspired Nanocomposite Material

“…Figure 4 shows the traction-separation relations in normal and tangential directions, which were used to govern the adhesive material behaviors. The cohesive zone model is widely used to study the composite material failure process [38,[43][44][45][46][47][48][49][50][51]. The adhesive tractions in the surface normal T n and tangential direction T t take the following form:…”