Research on hydro-mechanical deep drawing of double steps cylindrical part based on numerical simulation

In this paper, a research on the forming of the double step cylinder parts of AA6111 aluminum alloy material has been conducted. Two steps hydro-mechanical deep drawing is adopted to form the double steps cylinder parts, which can make the parts reach higher forming limit. Through applying finite element numerical simulation method, the influence of various parameters on the forming is studied and the influence of the hydraulic chamber pressure on the thickness distribution of double step cylinder parts is analyzed and optimized. The dangerous section occurred in the instability of double step cylinder is obtained by analyzing the stress and strain conditions during the forming process, and the variation of equivalent stress in plastic deformation is summarized. This method can solve the parts thinner or even rupture caused by the reverse pressure of suspended area, and it is suitable for forming the two steps parts which possess the characteristics that exists huge difference in bottom diameter and thin-walled complicated in shape.