Three-dimensional fracture and fragmentation of artificial kidney stones

The brittle fracture of a gypsum cylinder, which is used as an artificial kidney stone in lithotripsy research, is simulated by the use of the finite element method. The cylinder is submerged in water and is subjected to a pressure front parallel to one of its planar faces. The stresses induced by the pressure wave lead to fracture in the interior of the cylinder, with the formation of a spall plane located about 2/3 of the length from the face on which the pressure is applied. We show that the simulation reproduces the salient features of experimental observations.