Numerical assessment of impact resistance of rubberized metaconcrete with the modified K&C model

This paper presents a comprehensive numerical assessment of the impact resistance of a newly proposed protective material that combines the properties of metaconcrete and rubberized concrete. Significant efforts are dedicated to calibrating the material parameters within the K&C concrete model to improve the accuracy of the mechanical behavior description of rubberized concrete, ensuring consistency with experimental observations. Subsequently, the study primarily relies on "numerical spalling experiments" to evaluate the impact resistance of the proposed protective material. The results indicate that the inclusion of rubber aggregates can expand the bandgap of the metaconcrete, improve its energy absorption capacity, and alter the propagation characteristics of stress waves, thereby enhancing the material's impact resistance. Based on these findings, the mechanisms influencing the impact resistance of this novel material are further discussed and identified. The study identifies three key factors contributing to the enhanced performance of rubberized metaconcrete: increased matrix toughness, enhanced strain rate sensitivity, and an improved damping coefficient. The enhancement in toughness and strain rate sensitivity, respectively, increase the energy absorption capacity and dynamic strength of the matrix material, thereby reducing the damage caused by impact loads on the matrix of meta- concrete and ensuring the functional integrity of the metaconcrete. Additionally, the improved damping coefficient effectively broadens the bandgap range of the metaconcrete, allowing localized resonant wave attenuation to operate across a wider load frequency spectrum.