基于蠕变理论与有限元仿真的轨道交通车辆铝合金冲压件滞后回弹研究

滞后回弹是影响冲压件形状精度的关键因素。针对复杂工况下冲压件滞后回弹的预测与验证问题,提出了一种基于蠕变理论与有限元仿真方法。以轨道交通车辆司机室补强板为例,采用单轴拉伸试验测定了不同应力状态下5083-O铝合金材料的蠕变行为,并选用幂函数本构模型进行蠕变参数拟合;采用数值模拟手段分别建立了冲压成形、卸载回弹及滞后回弹的仿真模型,得到了不同阶段的应力演变及形状误差数据;开展了冲压件的成形试验,利用非接触式光学测量设备获取了冲压件静置2周后的滞后回弹量,并与理论结果和仿真结果进行对比。结果表明,仿真结果和试验结果中滞后回弹分布趋势一致,最大误差仅为0.069 mm;冲压件的最大滞后回弹量为0.32 mm,在实际生产中通过局部手工修磨即可满足焊装要求。

汽车铝合金覆盖件冲压成型工艺设计分析

随着我国经济的快速增长,综合国力的提升,使得人民生活水平直线上升,同时,还加大了城市化程度的建设进程。国内的很多领域都受到了冲击,这些冲击有好有坏,比如说交通领域,由于人们生活节奏的加快,使得城市内部的交通压力直线增长,进而推动了我国相关汽车领域的快速发展。但是,由于汽车车型繁琐的制造流程,使得传统的汽车制造技术已经不能很好的适用于当代的汽车制造领域,因此,汽车新技术的应用迫在眉睫。而在众多的新技术当中,铝合金覆盖件冲压成型技术就像一颗璀璨的明星,冉冉升起。

Springback analysis of 6016 aluminum alloy sheet in hot V-shape stamping

Springback behavior of 6016 aluminum alloy in hot stamping was investigated by a series of experiments under different conditions using V-shape dies and a finite element model which was validated reliable was used to further elucidate the springback mechanism. The effects of initial blank temperature, blank-holding force, die closing pressure and die corner radius were studied. It is found that springback decreases remarkably as the initial blank temperature rises up to 500 °C. The springback also reduces with the increase of die holding pressure and the decrease of die corner radius. Under different initial temperatures, the influence of blank-holding force is distinct. In addition, the bending and straightening of the side wall during the stamping process is found to interpret the negative springback phenomenon.