半球底筒形件充液拉深加载路径优化研究

Loading path optimization of hydro-mechanical deep drawing of the cup with a semi-ball bottom

针对半球底筒形零件充液拉深过程中悬空区形成的"软拉深筋",通过理论分析、数值模拟和工艺试验对与半球成形阶段直接相关的液压加载路径进行优化研究.理论推导得出液压载荷加载范围,并以其为基础进行多种加载路径条件下的数值模拟,获得不同加载路径对破裂关键点的壁厚及应变的影响规律,结合试验确定了合理的液压加载路径.结果表明:零件半球部分成形过程中破裂关键点在优化的加载路径条件下既可产生必要的有益摩擦,改善成形过程的应力应变状态,又可避免破裂关键点的过度减薄,提高了零件壁厚分布的均匀性和成形极限.

Aiming at the soft bear during hydro-mechanical deep drawing of the cup with a semi-ball bottom, loading paths were optimized by theory, simulation and experiment. The maximum fluid pressure via deep drawing displacement was obtained theoretically, and then the simulation was carried out under a few loading paths. Two key points to fracture：strain and thickness were analyzed, and reasonable loading path was validated experimentally. The results show that, during the process of the semi-ball forming, the optical loading path is beneficial for generating the helpful friction force, improving the stress-strain and avoiding the thinning; the uniform thickness and the forming limit are increased.