回弹对柱面扁壳类覆盖件刚度的影响机制  

Mechanism of Springback Influence on Stiffness of Automotive Cylindrical Shallow Panels

作　　者：邢忠文[1] 赵立红 杨玉英[2] 

机构地区：[1]哈尔滨工业大学机电工程学院,哈尔滨150001 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《机械工程学报》2008年第5期226-230,共5页Journal of Mechanical Engineering

摘　　要：利用能代表汽车覆盖件的柱面扁壳件为研究对象,建立与研究对象相一致的数学模型,对柱面扁壳件的成形、卸载回弹及刚度加载三个过程进行数值模拟,得到各个过程的几何及应力信息。通过改变成形工艺中的压边力得到扁壳件回弹量的变化,研究回弹对刚度影响的机理。对扁壳件的卸载回弹的研究结果表明:回弹后,沿柱面及曲面方向存在较大的残余压应力,且分布不均,是刚度发生变化的力学条件;曲面方向引起的曲率半径的变化及柱面方向的形状特点是刚度发生变化的几何条件。柱面扁壳件回弹量越大,残余压应力越大,且分布越不均匀,刚度越小;曲率半径越大,刚度越小,反之,刚度越大。The finite element models of cylindrical shallow shells that could represent automobile panels are established. Numerical simulations of forming, springback and stiffness of the cylindrical shallow shells are carried out. The geometric information and the stress of three simulation processes are obtained. Springback observed in cylindrical shallow shell is influenced by the variation of blank holder force （BHF）, and the mechanism of influence of springback on the stiffness is achieved. Based on the analysis of distribution of the stress-strain after cylindr/cal shallow shell form/rig and springhack, it is found that great residual compressive stress exists along the cylindrical and curved direction of shell. The residual compressive stree is in a state of uneven distribution, and the residual compressive stress is the mechanical condition for the variation of stiffness. The spring hack after stamping of the part resuits in a geometrical change, so the curvature radius of shell is the geometrical condition for the variation of stiffness. The greater the springback is, the greater the residual compressive stress will be, and the more uneven the distribution will be, and the smaller the stiffness will be. The greater the curvature radius is, the smaller the stiffness will be, and vice versa.

关 键 词：柱面扁壳件 数值模拟 回弹 压边力 

分 类 号：TG386[金属学及工艺—金属压力加工]