摘要

In this paper, a theoretical model of the shrinking metal tube is proposed. According to the relation between the actual die radius and the critical die radius decided by the tube and the conical die angle, the deformation is classified into three modes. Then, the published experimental data are used to validate the theoretical model. Within a large range of geometry parameters, numerical simulations are performed to confirm the applicable range of the current model. It is found that the compressional force, the final reduced radius and the equivalent plastic strain predicted are close to the simulation results for the conical angle smaller than 40 and radius-thickness ratio larger than 10. From the simulation results, several factors such as friction, dynamic effect, unsteady deformation stages, conical angle are analyzed. By comparing the tube shrinking and expansion, the energy absorption ability of shrinking tube is higher than expansion with the same deformation ratio. In the end, an optimization to maximize the specific energy absorption (SEA) is given for the shrinking tube.