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

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.