| 引用本文: | 徐虹,刘猛,国志鹏,邹玉杰,卢睿,谷诤巍,程秀明.动车组变曲率L型截面铝合金门立柱拉弯精度控制[J].哈尔滨工业大学学报,2021,53(2):77.DOI:10.11918/202006085 |
| XU Hong,LIU Meng,GUO Zhipeng,ZOU Yujie,LU Rui,GU Zhengwei,CHENG Xiuming.Accuracy control of stretch bending for variable curvature L-section aluminum alloy door column of EMU[J].Journal of Harbin Institute of Technology,2021,53(2):77.DOI:10.11918/202006085 |
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| 动车组变曲率L型截面铝合金门立柱拉弯精度控制 |
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徐虹,刘猛,国志鹏,邹玉杰,卢睿,谷诤巍,程秀明
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(吉林大学 材料科学与工程学院,长春 130022)
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| 摘要: |
| 对某动车组L型截面变曲率铝合金门立柱的拉弯成形过程进行模拟.基于不同阶段下的截面应力应变分布和回弹半径变化关系,探索了铝合金门立柱拉弯成形精度的影响因素,优选工艺参数及控制方法,并通过试验进行验证.结果表明:变曲率L型截面铝合金门立柱拉弯成形主要缺陷为截面畸变和回弹,其中截面畸变缺陷包括直线段区域腹板塌陷和圆弧端区域立边内凹.调整拉伸量等工艺参数一定程度上能够减小截面畸变缺陷和回弹.截面畸变缺陷主要因拉弯过程中立边受力不同引起.设置背压板,增加压板载荷能够减小直线段腹板截面畸变值；优化拉弯模具轮廓线,可降低圆弧端的立边截面畸变值.门立柱小圆弧端一侧回弹程度比大圆弧端一侧更严重,主要因变曲率铝合金门立柱两端不对称引起,影响门立柱的贴模度.利用回弹补偿法修正模具型面可有效控制回弹.试验最佳工艺参数为:预拉量1%,包覆拉伸量4.5%,补拉量0.5%,直线段区域施加40 kN背压力,构件成形精度大幅度提高,满足设计要求. |
| 关键词: 铝合金门立柱 变曲率L型截面 拉弯成形 数值模拟 精度控制 |
| DOI：10.11918/202006085 |
| 分类号:TG306 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(51790483); 吉林省科技发展计划项目(20160204058GX) |
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| Accuracy control of stretch bending for variable curvature L-section aluminum alloy door column of EMU |
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XU Hong,LIU Meng,GUO Zhipeng,ZOU Yujie,LU Rui,GU Zhengwei,CHENG Xiuming
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(College of Materials Science and Engineering, Jilin University, Changchun 130022, China)
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| Abstract: |
| The stretch bending process of the variable curvature L-section aluminum alloy door column of an electric multiple unit (EMU) was simulated. Based on the relationship between the stress and strain distribution of the cross-section and the spring-back radius at different stages, the factors affecting the precision of stretch bending process were systematically explored for optimizing processing parameters and controlling methods, which were then verified by experiment. Results show that the main forming defects during bending were corss-section distortions and spring-back, where the cross-section distortion defects were web collapse in straight section and concave deformation of vertical edge in arc segment. The defects of cross-section distortions and spring-back could be reduced to some extent, by adjusting the processing parameters such as the stretching amount. The cross-section distortions were mainly caused by different forces on the vertical side during the stretch bending process. By setting back plate and increasing its load, the distortion value of the web plate in straight section could be reduced. The optimization of the profile of the bending die could decrease the distortion value of the vertical edge section in arc segment. Moreover, the spring-back degree in the small arc side was more serious than that in the large arc side, which was mainly due to the asymmetry of both ends of the variable curvature aluminum alloy door column, affecting the part-mold contact gap of the door column. The spring-back could be alleviated via modifying the die surface by spring-back compensation method. The forming accuracy could be greatly enhanced to meet the design requirements when the amount of pre-elongation, wrap-elongation, and post-elongation was 1%, 4.5%, and 0.5%, respectively, and the back pressure applied to the straight section was 40 kN. |
| Key words: aluminum alloy door column variable curvature L-section stretch bending numerical simulation accuracy control |
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