Simulation of concrete dynamic fracture

Under dynamic tensile loadings, the fracture strength of concrete increases with the strain rate. The mesoscale FEM model of concrete is established according to the mortar and aggregate mechanical properties. Using ABAQUS UEL technique, the dynamic crack propagation path under different loading rates, which is normal to the interface of mortar and aggregate, can be calculated. The results show that, under the lower loading rates, the crack will deflect along the interface, while under the higher loading rates, the crack will grow straight through the interface. It can be seen from the results that the physical mechanism of strain rate effect in concrete is due to the fracture of aggregates.