基于灰色关联分析的轧制差厚板盒形件充液拉深成形工艺参数多目标优化

Multi-objective Optimization of Process Parameters for Tailor Rolled Blank Box Parts in Hydro Deep Forming Based on Grey Relation Analysis

目的 将充液拉深工艺引入轧制差厚板零件的成形,为了进一步掌握差厚板的充液拉深成形性能,对差厚板盒形件充液拉深成形过程进行研究。方法 通过理论推导获取临界液池压力公式,在此基础上运用数值模拟方法分析液池压力比对差厚板厚度减薄率和厚度过渡区移动量的影响,采用正交试验和灰色关联分析获取成形参数对差厚板盒形件成形性能的影响规律和最优参数组合,实现对差厚板盒形件充液拉深成形工艺参数的多目标优化。结果 随着薄-厚侧液池压力比的增大,差厚板最大厚度减薄率先减小后增大,过渡区移动量先增大后趋于平稳,薄-厚侧液池压力比为2较为合理。厚侧压边力、摩擦因数、薄-厚侧液池压力之比、薄-厚侧压边力之比、厚侧液池压力对差厚板盒形件充液拉深性能的影响程度依次减小。结论 采用灰色关联分析得到的最优工艺参数组合来完成差厚板盒形件的充液拉深成形,能够有效地抑制差厚板零件厚度的过分减薄及厚度过渡区的过度移动,进而提高差厚板的成形性能。

The work aims to introduce hydro deep forming process into the forming of tailor rolled blank, in order to further master the forming property of tailor rolled blank and study the hydro deep forming process of tailor rolled blank(TRB) box parts. The critical liquid pressure formula was obtained by the theoretical derivation. On this basis, numerical simulation method was used to analyze the effects of the liquid pressure ratio on thickness thinning of TRB and movement of thickness transition zone(TTZ). The orthogonal test and the grey relation analysis were adopted to obtain the effect laws of the forming parameters on the formability of TRB box parts and the optimal parameter combination, and the multi-objective optimization of process parameters for TRB box parts in hydro deep forming was accomplished. As the ratio of the liquid pressure on the thinner side to the liquid pressure on the thicker side increased, the maximum thickness thinning of TRB decreased firstly and then increased,and the maximum movement of TTZ increased firstly and then gradually became stable. It was reasonable for the ratio of the liquid pressure on the thinner side to the liquid pressure on the thicker side to be 2. The affecting extents of different factors on the formability of TRB box parts in hydro deep forming were listed as the blank holder force(BHF) on the thicker side, the friction coefficient, the ratio of the liquid pressure on the thinner side to the liquid pressure on the thicker side, the ratio of BHF on the thinner side to BHF on the thicker side and the liquid pressure on the thicker side as a descending order. The optimal process parameter combination obtained by the grey relation analysis is used for the hydro deep forming of TRB box parts, which can effectively restrict the excessive thickness thinning and TTZ movement of TRB parts, thus improving the formability of TRB.