钢丝绳捻制成形残余应力的理论与实验研究

Theoretical and experimental research on the laying residual stress of metal wire rope

采用共转坐标系弹塑性有限元法模拟了钢丝绳捻制成形过程 ,用数值计算和X射线实验分析结果探讨了捻制成形过程中的重要工艺参数反扭转系数Y对捻线加工残余应力分布和弹性恢复变形的影响规律 .研究结果表明 ,Y =0时 ,残余应力以捻线中心为轴呈轴对称一次螺旋状分布 ;用非零反扭转系数捻制成形时 ,钢丝绳股中钢丝的残余应力呈二次螺旋状不均匀分布 .Y <1.0时 ,捻线存在与捻制公转方向相反的扭转弹性恢复 ;Y =1.0时 ,存在着较大的弹性恢复 ;Y >1.0时 ,扭转弹性恢复与捻制成形的方向相同 ,形状冻结性好 .综合考虑钢丝绳成形性、使用安全性和抗拉强度 ,合理的反扭转系数最好取略大于 1.0 .

An elastic plastic finite element method with co rotational coordinate is adopted to simulate the laying forming of metal wire. With the help of numerical computation and X ray experiment, self rotating ratio Y is discussed, which is an important laying processes parameter to the distribution of forming residual stress and the elastic spring back deformation. The results have been obtained. The residual stress distribution of metal wire in a stranded rope is single helical twist around axis of the metal wire while Y =0.0; with nonzero self rotating ratio, the residual stress distribution is non uniform double helical twist. While Y <1.0, there is torsional elastic spring back in the opposite direction of laying revolution in the metal wire; Y =1.0, there is more elastic spring back; Y >1.0, the torsional elastic spring back is in the same direction of laying revolution and the shape stability is better. Taking shape stability, safety and tensile strength into consideration, the reasonable value of self rotating ratio should be slightly more than 1.0 .