Abstract:The experimental platform of liquid-driving expanding ring can effectively realize the dynamic fracture of the ductile metal ring under the high strain rate tensile load. In this work, the finite element simulation of fluid–structure interaction method was used to simulate the metal ring’s movement, deformation and fracture under the action of high-pressure liquid. This paper analyzed the influence of the contact stress between the device and the specimen in the fragmentation process, and discussed how to realize the effective loading by hydraulic pressure to the specimen. The simulation results show that the initial contact stress and the longer liquid load have little effect on the fracture process of the specimen. By giving the proper loading condition, the liquid-driving expanding ring device can absolutely satisfy the one dimension stress condition and the free expanding of the ring.