Damage behavior of high particle volume fraction composites with initial damage by finite element meso-modeling

Analyzing the deformation and damage processes of high particle volume fraction composites (HPVFCs) based on the meso-structure modeling plays an important role in their service lifetime and functional reliability. The reported mesoscopic structural models are usually ideal models without initial damage and apply to composites with the volume fraction of particles less than 80%. This work provides a new mesoscopic structure model called aggregate settlement-merging model to successfully simulate the mechanical behavior and damage mechanism of the polymer-bonded explosive (PBX) under quasi-static loads, and the macroscopic response is accurately predicted by the cohesive finite element method. This simulation commendably predicts the failure modes including interface debonding, binder filaments, and grain failure, which is consistent with the observation in micromechanical experiments. The multi-scale relationship between macroscopic mechanical properties and microscopic initial interface damage is quantitatively established in a form of an exponential function. This study shows a relationship between meso-structures and performance and provides strategy for designing next generation high-performance HPVFCs.