大型复杂截面铝型材挤压过程数值模拟及模具结构的优化

Numerical simulation on extrusion process of aluminum profile with large and complex cross-section and die structure optimization

以典型的GDX-11车辆底板型材为例进行模具结构设计,在Simufact 9.0商业软件平台上,采用基于Euler网格描述的有限体积法,实现了大断面复杂截面铝型材挤压过程的数值模拟,获得了挤压过程中金属的流动变形行为.通过模拟发现:采用原始模具挤压时,型材出口处的流速极不均匀,斜筋处出料困难,通过对模具结构进行修改及优化,在斜筋入口处增加引流槽及适当调整分流孔和工作带的尺寸,最终模拟挤出合格的型材,型材端面平整,出口处的流速均匀.

The GDX-11 vehicle floor profile was taken as an example to design the die structure. Based on Simufact9.0 commercial software, numerical simulation on extrusion process of aluminum profile with large and complex cross-gection was carried out using the Finite volume method （FVM） of Euler mesh description; and the metal flow and deformation behavior in extrusion process was obtained. It was found that the velocity at the die exit was non-uniform and the metal flow at the oblique ribs was hard. So, the modification and optimization of die structure design was carried out through adding the drainage groove at the inlet of oblique ribs, properly adjusting the dimension of portholes and die bearing. Lastly, the acceptable quality profiles with even extrudate head and uniform exit velocity in numerical simulation extrusion were obtained.