Numerical investigation on dynamic tensile fracture in concrete material by non-ordinary state-based peridynamics

To accurately predict the dynamic tensile fracture in concrete materials subjected impact and blast loadings, this study firstly establishes a modified Monaghan artificial bulk viscosity calculated method within the framework of a non-ordinary state-based peridynamics theory to eliminate numerical oscillations. And then, the previously developed corrected strain-rate method is implemented into the Kong-Fang model recently proposed to accurately calculate the strain-rate effect during sudden changes in strain-rate. Based on the two methods above, numerical simulations of elastic wave propagation in a one-dimensional rod are conducted, and the numerical simulations demonstrate that the modified Monaghan artificial bulk viscosity could effectively suppress the non-physical numerical oscillations caused by the deformation gradient approximation. Furthermore, the influence of the artificial bulk viscosity parameters is investigated, and recommended values of parameters are provided. Finally, the model is used to numerically simulate of the spall test in concrete specimens, in which effects of artificial bulk viscosity and different strain-rate computation methods on the predictions of dynamic tensile fracture are compared. The numerical simulation results demonstrate that accurately predicting the dynamic tensile fracture in concrete materials requires simultaneous considerations of artificial bulk viscosity and corrected strain-rate. The established non-ordinary state-based peridynamics model that accounts for both artificial bulk viscosity and corrected strain-rate shows a good capability in predicting crack locations and quantities. This work gains new insights for the numerical simulation of dynamic tensile fracture in concrete materials under impact and blast loadings.