铝合金大型薄壁构件电磁渐进成形数值模拟  

Numerical simulation of electromagnetic incremental forming for large thin-walled aluminum alloy components

作　　者：薛克敏[1] 刘超[1] 李萍[1] 严思梁 XUE Ke-min;LIU Chao;LI Ping;YAN Si-liang(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Shaanxi Key Laboratory of High-performance Precision Forming Technology and Equipment,Northwestern Polytechnical University,Xi′an 710072,China)

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009 [2]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074 [3]西北工业大学陕西省高性能精确成形技术与装备重点实验室,陕西西安710072

出　　处：《塑性工程学报》2022年第6期41-50,共10页Journal of Plasticity Engineering

基　　金：国家自然科学基金青年基金资助项目(51705119);陕西省高性能精确成形技术与装备重点实验室开放基金基金资助项目(PFTE-2020-KF-01);材料成形与模具技术国家重点实验室开放基金基金资助项目(P2021-015)。

摘　　要：为精确控制铝合金大型薄壁构件电磁渐进成形质量,基于LS-DYNA EM平台建立了铝合金大型薄壁构件双线圈电磁渐进成形三维有限元模型,通过数值模拟研究了双线圈放电时板料的动态变形行为,并探究了自由拉胀成形阶段放电电压、放电间隙、放电路径和偏转角度对成形质量的影响规律。结果表明:应力波由两线圈作用区域开始以近圆的形式向外传播,在板料中心处汇聚后沿双线圈中心连线垂直方向继续传播,直至动能耗尽;从双线圈作用区域到板料中心,等效应变逐渐增大,随着应力波不断传播,传播路径上单元的应变速率逐渐减小。采用小间隙、“低+高”的放电电压组合及较低的线圈偏转角度有利于提高成形深度及成形均匀性;相较于顺序放电,间隔放电可以提高成形深度,但成形均匀性稍有降低。通过得到的8道次间隔放电方案能获得最大的成形深度和最佳成形均匀性,最大平均成形深度达到47.4 mm,最小成形深度标准差约为4.01。To accurately control the electromagnetic incremental forming(EMIF)quality of aluminum alloy large thin-walled components,the three-dimensional finite element model of dual-coil EMIF of aluminum alloy large thin-walled components was established based on LS-DYNA EM platform.The dynamic deformation behavior of sheet metal under dual-coil discharge was studied by numerical simulation,and the influence of discharge voltage,discharge gap,discharge path and rotation angle on the forming quality was investigated in the free drawing and bulging forming stage.The results show that the stress wave starts from the action area of the dual-coil and propagates outward in a nearly circular form,and then continues to propagate along the direction perpendicular to the connecting line of the dual-coil centers after converging at the center of the sheet,until the kinetic energy is exhausted.From the action area of the dual-coil to the center of the sheet,the effective strain increases gradually,and the strain rate of the element along the propagation path decreases gradually with the continuous propagation of stress wave.The combination of small gap,“low+high”discharge voltage and low coil rotation angle is helpful to improve the forming depth and forming uniformity.Compared with the sequential discharge,the interval discharge can improve the forming depth,but the forming uniformity is slightly reduced.Using the eight-pass interval discharge scheme,the maximum forming depth and the best forming uniformity are obtained,with the maximum average depth of 47.4 mm and the minimum standard deviation of forming depth of about 4.01.

关 键 词：铝合金大型薄壁构件 电磁渐进成形 双线圈 动态变形行为 成形质量 

分 类 号：TG391[金属学及工艺—金属压力加工]