铝合金电阻点焊预压接触分析

Pre-press contact analysis of aluminum alloy resistance spot welding

为了探究铝合金电阻点焊的接触压力分布及初始导电区域,利用ABAQUS软件建立球面形电极条件下的预压接触二维轴对称有限元模型并对模型施加不同的电极压力.在可视化模块中得到了各个接触面上接触压力随载荷变化曲线、电极上的轴力分布云图及工件内的有效塑性应变云图.有限元分析结果表明,各接触面上的接触压力分布是不均匀的,电极-工件间的接触压力受电极球形端面轴向应力分布影响;工件间接触压力与材料所处状态有关;随着电极压力的增大,工件间接触半径呈线性增长.说明电阻点焊时可以通过选取不同截面的电极来改善接触压力的分布,进而改变初始导电区域的大小.

To explore the distribution of the contact pressure and the initial conductive region in aluminum alloy resistance spot welding,a preloading contact axisymmetric finite element model was created by ABAQUS software under the spherical electrode conditions, and the different electrode pressures were applied to the model. The contact pressure curves of different contact surfaces, axial force contours on electrodes and effective plastic strain contours within workpieces were obtained in the visualization module. The finite element analysis results show that the distribution of contact pressures in the contact area is not uniform, and the contact pressures between the electrodes and the workpieces are influenced by the spherical electrode tip axial stress distribution; the contact pressures between the workpieces are associated with material state; the contact radius between the workpieces increases linearly with the increasing of electrode pressures. It illustrates that the contact distribution can be improved by selecting different section electrodes to change the contact area in resistance spot welding.