Calibration Method of PFC3D Micro-Parameters under Impact Load

Micro-parameter calibration is essential in constructing an accurate and reliable numerical model of particle discrete element PFC3D 6.0 software. Micro-parameter calibration is mainly accomplished according to the macro-parameters obtained from static or quasi-static laboratory tests such as UCS. However, there is little current research concerning the calibration method under impact load. An SJM micro-parameter calibration method, based on the SHPB rock test and the FLAC3D/PFC3D coupling method, is proposed to solve this problem. Firstly, UCS, SHPB, and other laboratory rock tests were carried out to determine the rock sample’s macroscopic physical and mechanical parameters. Secondly, the FLAC3D/PFC3D numerical coupling model of the SHPB test was established, and the single-factor and double-factor orthogonal numerical simulation was carried out. Then, the main micro-parameters that affect the macroscopic physical and mechanical parameters of the SJM particle discrete element model were proposed. Finally, the quantitative relationship between the model’s macro-parameters and micro-parameters was established through multiple linear regression. A set of PFC3D micro-parameter calibration processes under impact load was established. The relative errors of the macro-parameters obtained from laboratory and numerical tests totaled less than 5%, which further verifies the rationality of the calibration method. This method provides some reference values for PFC3D micro-parameter calibration under impact load.