Simulations of meso-scale deformation and damage of polymer bonded explosives by the numerical manifold method

Polymer bonded explosive (PBX) is a particle-matix composite consisting of explosive particles, polymer matrix/binder, and the interface between the particles and the binder, and the particle volume fraction (PVF) in the PBX is extremely high. To simulate the meso-scale deformation and damage behaviors of PBX with the numerical manifold method (NMM), a bilinear cohesive contact relationship (BCCR) model with three parameters is incorporated in the NMM to describe the particle-binder interface, a visco-elastic constitutive model of prony series with 22 parameters is incorporated in the NMM to describe the polymer binder, and a fracturing algorithm based on the maximum tensile stress criterion and the Mohr-Coulomb criterion is employed to describe the fracturing failures of the particles as well as the binder. The PBX meso-scale deformation and damage process of microcrack initiation, crack propagation and formation of crack bands under tensile or compressive conditions are studied through NMM simulations, and the influenes of the PVF and the explosive particle geometrical distribution (PGD) on PBX mechanical performaces are specially investigated. This work enables and proves the NMM to be an promissing roubust numerical tool for further simulation studies of the meso-scale mechanical performances of PBX, as well as other particle-fillled polymer composites.