大尺度U形板材工件鼓形翘曲缺陷分析及消除

为研究折弯成形工件翘曲的形成机理,提出了一种采用实验、数值模拟和理论分析相结合方法.以一大尺度半椭圆形工件成形为例,对该工件渐进折弯中非均匀回弹翘曲全过程进行ABAQUS有限元数值模拟.分析指出大折弯力、折弯机床身变形是工件鼓形翘曲的主要原因.实施了采用凹模大开口、折弯机床身变形反向挠度补偿的工件缺陷消除措施.工程应用结果表明,该方法对提高工件的成形精度及消除工件翘曲变形缺陷等均获得满意的效果.

Analysis and elimination fordrum warpage of U-shaped workpiece with super length and large opening of sheet metal

To study the mechanism of workpiece warpage under air-bending forming,a method combined experiment with numerical simulation is proposed in this paper.Through forming a semiellipse-shaped workpiece with super length and large opening,non-uniform springback processes for the formed workpiece are simulated by ABAQUS finite element platform.It is pointed out that large bending force and bed deformation of press brake can lead to warpage defect of workpiece.A technique used reverse deflection compensation for bed deformation of press brake and female die with large opening is found to eliminate warpage defect of workpiece.Manifested by the experiment for incremental air-bending forming of this workpiece,the method proposed yields satisfactory performance in improving forming accuracy and eliminating warpage defect of large workpicec.