2024铝合金薄壁马鞍形尾椎上壁板半管零件的双层板液压拉深成形工艺

Hydraulic deep drawing process with double-layer plate for 2024 aluminum alloy thin-walled saddle-shaped upper wall plate half-pipe part

为解决某国产飞机上某2024铝合金薄壁马鞍形尾椎上壁板半管零件在传统落压以及蒙拉中容易产生的破裂、起皱、表面质量差等问题,采用液压拉深工艺,综合考虑尾椎上壁板半管零件的马鞍形脊线在成形过程中导致的局部失稳现象,借助双层板辅助成形的思想,解决了零件尾部流料问题。利用有限元软件建立了有限元模型,对2024铝合金薄壁马鞍形尾椎上壁板半管蒙皮件的双层板液压拉深工艺进行了数值模拟。通过模拟分析,结合双层板液压拉深成形过程中对辅助板料的要求,确定了辅助板料的屈服强度的范围;根据材料变形能力和零件结构形状,优化了充液加载时的最大液室压强。模拟得出的最优结果为:辅助板料的屈服强度应在174 MPa以上,最大液室压强为15 MPa。最后对模拟结果进行了实验验证,试制出了合格的马鞍形尾椎上壁板半管零件,为此零件的成形提供了一套符合工业生产要求的工艺方法,对此类形状零件的成形具有很大的借鉴作用。

In order to solve the problems of cracking, wrinkling and poor surface quality of an 2024 aluminum alloy thin-walled saddle-shaped upper wall plate half-pipe part for tail vertebra on a Chinese aircraft in the traditional drop pressure and stretching, the hydraulic deep drawing process was adopted, and considering that the saddle-shaped ridge line of the upper wall plate half-pipe part for tail vertebra caused local instability during the forming process, the problem of material flow at the end of part was solved with the aid of the double-layer plate auxiliary forming idea. Then, the finite element model was established by finite element software, and the hydraulic deep drawing process with double-layer plate for 2024 aluminum alloy thin-walled saddle-shaped upper wall plate half-pipe skin part for tail vertebra was simulated numerically. Furthermore, through the simulation analysis, combined with the requirements of auxiliary sheet in the process of double-layer plate hydraulic deep drawing, the yield strength range of auxiliary plate was determined, and according to the deformation ability of materials and the structural shape of part, the maximum liguid chamber pressure of liquid filling was optimized. The optimal simulation results show that the yield strength of the auxiliary plate should be above 174 MPa, and the maximum liquid chamber pressure is 15 MPa. Finally, the simulation results are verified by experiments, and the qualified saddle-shaped upper wall plate half-pipe parts for tail vertebra are produced, which provides a set of process methods in line with industrial production requirement and has great reference significance for the forming of such shaped parts.