An Integrative Model for the Dynamic Behavior of Brittle Materials Based on Microcracking and Breakage Mechanics

This study presents an enhanced integrative constitutive model for brittle materials subjected to dynamic loading by combining a micromechanics-based damage model and a breakage mechanics model. The damage model was used to describe microcracking, which captures the initial fragmentation of brittle solids due to growth of cracks until the material transforms into a granulated material. The dynamic behavior of the granulated material was described with a breakage mechanics model, which is activated when the damage level reaches a predefined critical threshold. The response of reference material boron carbide was simulated under confined/unconfined compression and ballistic impact loading conditions. The predictive capability of the integrative model was investigated by comparing the unconfined and confined simulation results with experimental data quantitatively and qualitatively. The simulations were also performed with an integrative model adopting a Drucker–Prager based two surface model to investigate the role of the granular material model on the macroscopic dynamic response. The two integrative models, which provided similar failure strength values under unconfined compression, predicted considerable different damage pattern in sphere impact simulations. A series of sensitivity simulations revealed that some critical granular model parameters strongly control the extent and spatial distribution of damage, and penetration resistance. The sphere impact simulations conducted with different impact velocities were able to reproduce various deformation features observed in previous experimental studies. The capability of the integrative model in capturing many aspects of the dynamic response of brittle materials under different loading conditions suggests that it can provide useful guidance for the design and development of next generation materials.