Mesoscopic Insight into the Damage Mechanism for the Static Preload Effect on Dynamic Tensile Strength of Concrete

Abstract

Experimental studies have showed that the static preload increases the dynamic tensile strength of concrete under certain conditions. But its mechanism still remains open. In this study the authors focus on the dynamical damage failure mechanism of concrete with the static preload, and propose a mesoscopic damage dynamical model to evaluate the elastic modulus and strength enhancement parameters of concrete that is considered as a three-phase heterogeneous composite material. A mesoscopic dynamical model is developed to implement the numerical simulations of dynamic flexural-tensile damage and failure processes of concrete under shockwave and cyclic triangular wave loads. The numerical results agree well with the experimental ones reported in previous studies. This study illuminates that the static preload has an enhancement effect on the dynamic tensile strength. Such an effect essentially results from the double-sided features of the strain rate enhancement and damage deterioration of concrete.