铝合金板材异步轧制翘曲缺陷的有限元数值分析

Numerical study on warp defects of aluminum alloy sheets during the asymmetric rolling

利用非线性有限元数值模拟方法,对异步轧制过程中轧板金属流动的速度场、应变场、变形区内由摩擦引起的"搓轧区"现象及附加剪切变形区的受力进行研究,并分析这些因素对翘曲的影响规律。结果表明,由于轧板上下部分变形速度不同,在稳定轧制阶段始终存在速度差,导致轧向和法向的变形不对称,并引起轧板厚向上不同部位产生应变差,最终导致翘曲。另外,由于"搓轧区"上下两部分所受轧辊摩擦力方向相反,由此产生的正弯矩和贯穿轧板厚向的附加剪切变形,也是引起翘曲的重要因素。

Using the nonlinear FE numerical simulation method, the velocity field, strain field, the contact frictional stress and additional shear stress within the deformation zone during the asyrranetric rolling （ASR） of aluminum alloy sheet were investiga- ted, and the effects of these factors on the sheets＇ curvature were also analyzed. The results show that the differences of the met- al flow velocity existed along the sheet thickness until the stable rolling stage occurred, which could induce the strain differences in the rolling direction and promote the formation of the sheet curvature. Due to the opposite frictional stress in the cross-shear zone, the bending moment and the additional shear deformation through the sheet thickness can be induced, which should be an- other reason for the bending deformation during the asymmetric rolling of aluminum alloy sheets.