Peridynamic modeling of dynamic damage of polymer-bonded explosive (PBX) with sensitivity analysis

Polymer-bonded explosive (PBX) is one of the typical heterogeneous composite materials and dynamic damage processes are crucial for understanding its behavior. The present study establishes a comprehensive peridynamic (PD) framework to model dynamic damage of PBX with sensitivity analysis of model parameters. The PD model successfully captured the various characteristics of PBX damage evolution: energetic crystal damage dominated under low-velocity impacts (20 m/s), while interfacial damage contributions increased substantially at higher velocities (40–60 m/s). Moreover, the importance of the total nine PD model parameters belonging to three different materials regarding total bond damage and damage modes (trans-granular/inter-granular) under 20–60 m/s impact loading is quantified based on the established three-dimensional PD model of steel-encased PBX. The Kriging surrogate model from PD model parameters to PBX damage is also constructed to decrease the computational cost. The sensitivity analysis revealed that binder failure strain exerted significant influence on total mechanical damage at different velocities. Notably, Young's modulus of energetic crystal demonstrated strong cross-mode effects at elevated velocities, governing both trans-granular crack initiation and inter-granular debonding, thereby emerging as a critical constitutive parameter for relatively high impact velocity. The current study offers a useful computational framework to evaluate how the uncertainty of PBX properties impacts its dynamic damage response.