Meso-scale fracture simulation of high particle-filled composites using the numerical manifold method

High particle-filled composites (HPFCs) are widely used in protective structures, aerospace components, and energetic materials due to their high density, superior mechanical properties, and multifunctionality. However, their complex meso-structures give rise to highly nonlinear and multi-scale coupled deformation and fracture behaviors under tensile loading. In this study, crack-insertion and element-deletion algorithms were developed within the framework of the Numerical Manifold Method (NMM) to simulate the meso-scale fracture processes of HPFCs. Representative volume elements (RVEs) were constructed with distinct constitutive models for particles, matrix, and interfaces to investigate the effects of particle filling ratio, temperature, and strain rate on the mechanical response. Results indicate that low filling ratio models exhibit multiple crack bands, whereas high filling ratio models develop a single dominant crack band. Increasing filling ratio enhances the equivalent elastic modulus but reduces failure strain, with tensile strength remaining nearly constant. Temperature rise softens the matrix, shifts crack initiation toward the bottom, and suppresses transgranular fracture of particles. At high strain rates, fracture evolves into multiple crack bands, with increasing modulus and decreasing failure strain. Comparison with experimental data at 25 °C, strain rate of 0.67s⁻¹, and particle volume fraction of 90.102% shows simulation errors below 2% for both modulus and strength, confirming the accuracy of the method. Overall, the proposed NMM-based approach effectively captures critical fracture features such as crack-band evolution and interfacial debonding, and provides accurate predictions of HPFCs mechanical responses under varying service conditions, offering valuable insights for material design and optimization.