A new damage-based nonlocal model for dynamic tensile failure of concrete material

Abstract

When concrete structures subjected to the blasts and high velocity impact loadings, dynamic tensile failure (e.g. spall) is frequently observed. It is known accurate prediction of dynamic tensile failure is a challenging problem. In the present study, a new damage-based nonlocal model is proposed to predict the dynamic tensile failure of concrete material, which is based on the local Kong-Fang concrete material model recently proposed (Int J Impact Eng 2018, 120: 60–78). In this nonlocal model, the interaction domain decreases with the increase of local damage, which leads to a desirable description of the localization at total damaged regions and free surfaces, i.e., non-localities vanish at these regions. Numerical examples of a 1D spalling test and a 2D dynamic tension test of a concrete plate demonstrate that the damage-based nonlocal model can resolve all the limitations of original nonlocal models. The damage based nonlocal model is then validated against two experiments, namely, the Split Hopkinson Tensile Bar (SHTB) test and the Modified Split-Hopkinson bar (spalling) test. Numerical simulations show that, the proposed nonlocal model can reasonably predict the dynamic tensile failure location. But the local model cannot correctly predict the dynamic tensile failure, and the original nonlocal model cannot predict the multiple cracks under intense loading rate.