Dynamic Spallation in Fiber Reinforced Concrete under Impact Loading

In this paper, a model for fracture and fragmentation, considering the heterogeneity of material properties, is employed to investigate the mechanism of spallation in fiber-reinforced concrete with various fiber and aggregate contents under impact loading. Numerical simulations show that there is a marked difference in the failure patterns among concrete with various fiber and aggregate content,s and the fibers can remarkably improve the tensile strength of the concrete, effectively preventing the initiation and propagation of cracks and inhibiting the occurrence of spallation. Moreover, numerical simulations capture the whole process of the propagation of incident compressive stress waves in the fiber reinforced concrete and the reflection of stress wave on concrete surface and the spallation failure of fiber-reinforced concrete induced by the reflected tensile stress wave, which is obviously different from the failure pattern of fiber reinforced concrete under static loads. The results in this study can provide some valuable reference for studies on the tensile properties and failure modes of heterogeneous quasi-brittle materials.