Mechanical behavior simulation of particulate-filled composite at meso-scale by numerical manifold method

•A continuous-discontinuous coupling method is developed to simulate the mechanical behavior of particle highly-filled composite (PFC).•According to the mechanical behavior of explosive grains and binders, elastic-viscoplastic and visco-elastic constitutive models are proposed and implemented in NMM program framework, respectively.•The debonding criterion of interfacial cohesion and the fracture criterion of explosive particles are developed, and the microscopic debonding and fracture phenomena of PFC are simulated.•Based on the meso-damage evolution law, the macro-damage evolution equation of PFC is derived.•Based on the viscoelastic behavior and damage evolution behavior of PFC, the visco-elastic damage constitutive model of PFC is derived. Particulate-filled composite (PFC) is a kind of mixed multi-phase material with the grains highly embedded in the binders with ratio higher than 90%. Its good mixture capacity with the binder, in particulate or fibre form, leads to composite materials with intermediate properties that result from the combined action of the constituents. Due to the complexity of PFC meso-scopic composition and loading levels, it is difficult to reveal the deformation and damage mechanism of composites by traditional phenomenological macro-scale methods. In the present work, based on the PFC meso-structures with highly-filled grains, the numerical manifold method is utilized to simulate the meso-scale mechanical response of PFC at different loading levels. The effects of strain rates and temperatures on the meso damage morphology of PFC are studied. The damage evolution laws caused by interfacial debonding and micro-cracks in the meso structure are analyzed. Based on their isotropic assumption, the macroscopic equivalent damage evolution equations caused by these meso-scale damages are derived, respectively. The effects of loading levels on the mechanical characteristic parameters (such as modulus, failure strength, ultimate strain, etc.) are also discussed quantitatively. The specific mathematical expressions of the strain rate and temperature dependent properties under uniaxial tension/compression are statistically obtained. Two categories of constitutive models of coupling damage evolution equation with Johnson-cook and generalized Maxwell model are proposed to describe the macroscopic equivalent mechanical behavior of PFC. A numerical manifold method (NMM) was developed to simulate the meso-scale mechanical behavior of particle fill