铝合金汽车顶盖充液成形的数值模拟

目的研究铝合金汽车顶盖拉延工序的充液成形工艺。方法基于有限元分析软件Dynaform,利用带局部刚性凹模整形的被动式充液成形工艺,通过建立有限元分析模型,优化成形过程中的关键工艺参数,分析变形规律并进行质量控制。结果成形过程中的液室压力加载路径、压边力、拉延筋,以及坯料形状等工艺参数对成形影响较大。液室压力不宜过早加载。液室压力过大或压边力过小不利于顶部产生充分塑性变形。压边力过大极易造成顶盖圆角处的破裂。结论该成形工艺可行,且数值模拟的准确性及适用性较高,采用该成形工艺可得到表面质量良好,未出现起皱、破裂缺陷的合格零件。

Numerical Investigation into the Hydroforming of Aluminum Alloy Automobile Roof Cover

To study the hydroforming process for aluminum alloy automobile roof cover drawing operation. By means of the passive hydroforming process with local rigid die shaping, the key process parameters in the forming process are optimized, the deformation rules are analyzed, and the quality control is carried out using the finite element analysis model in the finite element analysis software Dynaform. The results show that the process parameters such as cavity pressure loading paths, blank holder force, drawbead, and blank shape during the forming process have a greater impact on the forming. The cavity pressure should not be prematurely loaded. Excessive cavity pressure or excessive blank holder force is not conducive to having full plastic deformation for the top of the roof cover. Excessive blank holder force can easily cause the rupture at the corner of automobile roof cover. It can be known that the forming process is feasible, and the accuracy and applicability of the numerical simulation are high. The qualified parts with better surface quality and no wrinkling and cracking defects can be obtained by the forming process.