大尺寸封闭截面铝型材拉弯工艺研究

Stretching bending for aluminium profile with large dimension section

本文以数值模拟为手段 ,利用大型商业化有限元软件Pam Stamp ,针对铝型材框架式车身生产中的关键技术———铝型材高精度弯曲成形进行了深入系统的研究 ,模拟了大尺寸封闭截面铝型材AA60 82 (T1状态 )在不同弯曲半径下的拉弯成形过程。研究结果表明 ,铝型材拉弯成形极限主要受脱模、起皱及壁厚减薄的限制 ,而成形精度主要受回弹和截面变形的影响。截面形状、弯曲半径和拉伸量是铝型材拉弯工艺中的 3个重要参数 ,确定正确的拉伸量是拉弯工艺成败的关键。文章通过对计算结果的分析 ,提出了上限拉伸量和下限拉伸量及相应的确定方法 。

In the paper, the stretching-bending processes for th e aluminium profile AA6082 T1 with large dimension section are studied by simula tion using the dynamical FEM program Pam-Stamp. It is showed that the aluminium profile stretching-bending forming limit is mainly affected by wrinkle, deviat ing from die, wall thinning etc, and springback and section distortion have domi nant influence on bending forming precision. It is pointed out that the stretchi ng elongation is the key parameter for profile stretching-bending process. The principle for deciding the stretching elongation is presented and the region of stretching elongation is discussed.