JHR constitutive model for rock under dynamic loads

In consideration of the failure characteristics and patterns of rocks under strong dynamic loads, the Johnson-Holmquist-Rock (JHR) damage model is proposed based on the Johnson-Holmquist ceramic (JH-2) model, the rheological-dynamical analogy (RDA) model, and Liu's model. The proposed model comprehensively considers the strain rate effect and the deformation and failure mechanisms caused by energy flow. In order to apply the JHR model for the numerical simulation of rock-like materials, secondary development of the model is performed in the commercial software LS-DYNA, and model parameters are determined. The model parameters are then used to simulate a projectile impacting a granitic rock target and a blasting test. The numerical simulation results indicate that the JHR model is able to predict the shape of a conical plug caused by rock failure under a projectile impact, and it can simulate the failure process of rock under a blasting load. The simulation results are in good agreement with the experimental results.