中文摘要：

链模式成形是一种新型的板金属成形工艺,对链模式变截面成形过程中的材料流动规律和特点进行了计算机模拟仿真。模拟结果表明：变截面成形件的弯角处最大主应变较大,方向垂直弯曲面向外,边腿的凹弧区域最大主应变为拉应变,沿边腿的高度方向从高到低,最大主应变逐渐减小;边腿高度和成形角度对成形件纵向应变的影响较大,增大边腿高度和成形角度会增加边腿的纵向应变,材料属性对成形件的纵向应变影响较小。提取了仿真模型里变截面零件的纵向应变,结果显示,在变截面型材边腿上的4个圆弧位置纵向应变比较大,它们在成形的过程中发生了拉伸或者压缩的变形,而等效塑性应变主要集中在变截面型材的弯角部分。通过链模式变截面成形实验对模拟结果进行验证,实验结果与仿真结果基本吻合。

英文摘要：

Chain die forming is a new type of sheet metal forming process. The material flow law and characteristics of chain die forming process were studied through simulation. The analysis results show that the maximum principal strain at the corner of the variable section forming part is larger,and the direction is perpendicular to the outside bending surface; the maximum principal strain at the concave arc region in the flange is tensile strain,which decreases along the height direction of flange from high to low; the flange height and forming angle have great influence on the longitudinal strain of the forming part,and increasing the height of the flange and forming angle can increase the longitudinal strain of the flange; the effect of material properties on the longitudinal strain of the forming part is small. The longitudinal strain of the variable cross section was extracted from the simulation model. The results show that the four arc zones in the flange of variable cross section part have larger longitudinal strain,where tensile or compressive deformation occur during forming process,but the equivalent plastic strain mainly concentrates in bending areas of variable cross section part. The simulated results were verified through experiment of chain die forming of variable cross section tests,and the experimental results are in good agreement with the simulation results.