薄壁铜管固定芯头振动拉拔过程中的摩擦分析

Analysis on friction of fixed rod of thin-walled copper tube in the drawing process with vibration

在拉拔过程中引入振动时,由于塑性成形中的"表面效应",可以减小拉拔成形过程中的摩擦力。基于有限元软件Marc,采用修正的滑动库仑摩擦模型,建立了薄壁铜管固定芯头振动拉拔模型,并对振动拉拔过程的摩擦与拉拔速度对摩擦的影响进行了数值模拟。结果表明:在薄壁铜管固定芯头拉拔过程中添加纵向振动可以减少铜管内外表面平均摩擦力,且幅值越大,频率越高,铜管内外表面平均摩擦力越小;拉拔速度为0~20 mm·s^(-1)时,随着拉拔速度增大,铜管内外表面平均摩擦力递增且上升趋势明显,拉拔速度大于20 mm·s^(-1)时,拉拔速度增大,铜管内外表面平均摩擦力增大,但增大的幅度小。

The friction can be reduced in the drawing process due to the surface effect of plastic forming by introducing vibration. The model of drawing with vibration for fixed rod of thin-walled copper tube was established by correcting the new Coulomb friction sliding model based on Marc software,and the influences of drawing speed to the friction in the drawing process were simulated numerically. The simulation results show that the average friction of inner and outer surfaces of thin-walled copper tube can be reduced by introducing longitudinal vibration,and the greater amplitude,the higher frequency,the smaller the average friction of inner and outer surfaces of thin-walled copper tube. When the drawing speed is 0 to 20 mm·s^-1,the average friction of inner and outer surfaces of thin-walled copper tube rise significantly with the increase of drawing speed. While the drawing speed exceeds 20 mm·s^-1,with the drawing speed increases,and the average friction of inner and outer surfaces of thin-walled copper tube increases slowly.