Calculation method of HJC constitutive model parameters of natural joint angle slate

Abstract In the course of underground engineering, geological conditions of layered slate are often encountered. Understanding the mechanical characteristics of layered slate is a prerequisite for engineering construction and disaster prevention and mitigation. As a result, at the beginning of the project, a large number of indoor tests were required, which is time-consuming and laborious. At the same time, the natural joint angle of the layered slate is random, so it is extremely difficult to establish a database of the mechanical characteristics of the layered slate. Therefore, it is urgent to find a simple and feasible method to determine the mechanical characteristics of the layered slate at a natural dip angle. Static test, Split-Hopkinson-Pressure-Bar (SHPB) test, and sensitivity analysis method are used in this paper. Taking five special joint angles (0 °, 30 °, 45 °, 60 °, 90 °) slate as the research object, the calculation method of Holmquist-Johnson-Cook (HJC) constitutive model parameters of natural joint angle slate are constructed, and the relationship between the HJC model parameters and the joint dip angle of slate is deduced. The results will provide a simple and feasible numerical simulation method for slate dynamics analysis.