Fracture behavior simulation of energetic single-crystal particles in polymer bonded explosive with 3DNMM

Polymer-bonded explosives (PBXs) are typical composite materials whose mechanical safety critically depends on the fracture behavior of embedded single-crystal particles under loading. However, the three-dimensional crack evolution process at the single-particle scale remains insufficiently studied. To address this gap, this work systematically investigates the mechanical response and failure process of single-particle PBX under 3D compressive loading. Particle models with various shapes, sizes, and loading positions—including spherical, ellipsoidal, and irregular polyhedral geometries—are constructed. A novel three-dimensional numerical manifold method (3DNMM) framework is developed, incorporating a crack initiation algorithm based on the maximum principal stress criterion and a wavy crack tip tracking algorithm. Using this method, the fracture behavior of different particle models is numerically simulated, with detailed analysis of crack initiation locations, propagation paths, and through-crack patterns. Simulation results show that particle geometry significantly influences stress distribution and crack morphology during compression. In particular, irregular polyhedral particles with fewer faces demonstrate stronger fracture resistance, while smoother and more symmetric particles are more prone to failure. This study presents a new approach for simulating 3D particle-scale fracture in PBXs and provides important theoretical insights for mechanical analysis and structural optimization of explosive materials.