Study on stress variation law of hard concretion coal under the action of pick based on DYNA

Modeling and simulation of pick cutting hard concretion coal process are taken as a key link to analyze the stress variation law. To this aim, the properties of hard concretion coal in the target mining area were tested. Related model with high-quality common grid was generated using the mapping method through Hypermesh. the coal breaking process was performed using LS-DYNA, and the stress variation law of coal and hard concretion was analyzed. The results showed that the closer the action position to the middle point of long axis of hard concretion, the greater stress peak would be generated, stripping of the pick occurred when it acted on the 2/5 and 1/2 positions of the long axis. Using similarity theory, the model of hard concretion coal was made and the pick cutting experiment was performed. Compared with simulation torque result, the correctness of modeling and simulation has been verified.