Abstract：The evolvement of rock damage impacted by high pressure water jet is simulated with nonlinear FEM and dynamic rock damage model. The numerical results show that most of rock damage and breakage take place in several milliseconds，the main damage behavior under a general continual jet is tensile damage caused by the rock unload and the jet impacting，and the evolvement of rock damage shows step changed. The effect of water jet parameters on rock breaking is studied. The numerical results agree well with experimental results，so that the method established in this paper can simulate rock breaking under high pressure water jet and the study results can be used to design and optimize rock breaking under water jet.
