球底筒形件主动径向加压充液拉深的数值模拟

基于低塑性、大高径比铝合金板材零件成形需求,提出了主动径向压力充液拉深新技术.通过数值模拟方法,对5A06铝合金球底筒形零件主动径向加压充液拉深成形过程进行了研究.采用基于LS-DY-NA3D内核的动态显示分析软件ETA/Dynaform5.5,根据成形工艺的特殊性,提出了液压载荷施加方法;依据球底零件变形时悬空区大小和曲率半径确定了合理的加载路径,并分析了主动径向压力和液室压力对零件成形过程和零件壁厚分布的影响,讨论了成形过程中出现的缺陷.研究结果表明,采用合理匹配的主动径向压力和液室压力加载路径,可有效地降低板料成形时的径向拉应力,抑制零件球底部的过度减薄,显著提高铝合金球底零件的拉深极限.

Numerical simulation of hydrodynamic deep drawing with independent radial hydraulic pressure of aluminum alloy cylindrical cup with a hemispherical bottom

To satisfy the forming need of low plasticity materials and large height-diameter ratio parts,a new process of hydrodynamic deep drawing(HDD) with independent radial hydraulic pressure was proposed.Aiming at 5A06 aluminum alloy cylindrical cup with a hemispherical bottom,HDD with independent radial hydraulic pressure was studied by means of numerical simulation.By employing the dynamic explicit analytical software ETA/Dynaform based on LSDYNA3D,and according to the forming process,a method to load hydraulic pressure was put forward.Based on the suspended region size and the curvature radius, the reasonable loading path was determined.And the effects of independent radial hydraulic pressure and liquid chamber pressure on the forming process and the sheet-thickness distribution were analyzed.The defects forming during forming process were discussed.The results indicated that the reasonable match between independent radial hydraulic pressure and liquid chamber pressure could reduce the radial tensile stress,restrain the serious thinning at the bottom of hemisphere and increase the drawing limitation of aluminum alloy cylindrical cup.