期刊论文

Defects formation mechanism and precision control of exit flow velocity in porthole die extrusion of hollow thin-walled aluminum profile

中文

中国有色金属学报

1004-0609

2021

31

04

917-930

10.11817/j.ysxb.1004.0609.2021-39670

52005244:国家自然科学基金 18B285:湖南省教育厅科学研究项目 2019JJ50510:湖南省自然科学基金

本校为第一机构

以汽车防撞梁为典型研究对象,开展型材分流模挤压试模出现的内加强筋壁厚减薄和开裂等缺陷产生机理研究,并提出挤压出模口横截面流速均匀性的精确控制方法。首先,基于任意拉格朗日-欧拉混合算法建立了型材分流模挤压稳态有限元模型。然后,基于材料流速均方差和焊合压力评价揭示型材挤压壁厚减薄和焊缝开裂的产生原因。最后,为了实现对出模口型材横截面流速的均匀控制,提出了"优化分流孔/引流槽、增添阻流块、基于Kriging近似模型和多岛遗传算法优化工作带"的分流模结构多步优化设计方法。结果表明:优化后出模口型材横截面流速均方差由23.75 mm/s减少到1.63 mm/s,型材壁厚尺寸误差小于0.1mm。同时...

Taking the automobile collision beam as a typical research object, the formation mechanism of extrusion defects, such as wall thickness thinning and cracking, on internal stiffener of profile in porthole die extrusion was revealed. The method for accurately controlling the uniformity of cross-sectional velocity at die exit was proposed. Firstly, an accurate steady-state finite element model for simulating the porthole die extrusion process of profile was established based on the arbitrary Lagrangian-Eulerian formulation. Then, the formation mec...