Experimental research and numerical simulation of the dynamic cylinder upsetting

In order to study the dynamic effects under impulsive load, experimental and numerical investigations on the dynamic upsetting process of lead cylinder were conducted. Experiments were carried out on a drop hammer impact test machine. The results show that the dynamic effects on the forming load is related to the hammer velocity, radius-height ratio of specimen and drop mass. The forming load increases with the increase of the hammer velocity or radius-to-height ratio. The fluctuation of load-displacement curve becomes obvious with the increase of the hammer velocity and drop mass. The deformation processes were simulated by the finite element program ANSYS/LS-DYNA. The deformed configuration, velocity vector field and equivalent strain distribution were obtained. The results show that the deformed geometry exhibits mushroom, the material points in the upper region flow faster than that in the lower region, and a strain concentration zone appears in the upper center region.