面畸变是指零件在成形中产生的局部起伏,变截面变曲率铝饰条零件在拉弯成形过程中易产生面畸变,对整车外观质量有很大的影响,面畸变的形成机理研究对于面畸变的预防和控制具有重要的指导意义.开展了铝饰条的拉弯成形面畸变缺陷形成机理研究,进行了拉弯成形试验及面畸变测量,通过Abaqus软件平台建立了铝饰条拉弯成形仿真模型,对铝饰条零件和特征件的局部变形进行了应力应变分析,分析了面畸变形成的过程.结果表明:该类饰条类零件的截面宽度与拉弯成形弯曲半径比值大于35%时,零件产生翘曲趋势,截面形状、上模具和垫料的共同作用导致局部面畸变的产生.

Surface defects refer to the local undulation of the parts in the forming process. The variable cross-section and variable-curvature aluminum trim parts are prone to local surface defects during the stretch-bending process, which has a great impact on the appearance of the whole vehicle. Research on the formation mechanism of surface defects has important guiding significance for the prevention and control of surface defects. In this paper, the formation mechanism of the deformation defects of the stretch-bending forming surface of aluminum trim is studied, the stretch-bending forming test and the surface defects measurement are conducted, and the simulation model of the stretch-bending forming of aluminum trim is established by using the Abaqus software platform. In addition, the forming process of surface defects is analyzed. The results show that when the ratio of section width to bending radius is larger than 35%, the part will have a warping tendency, and the joint action of section shape, upper die, and padding will cause local surface defects.