电动门窗升降器用钢丝绳疲劳断丝分析

Wire fatigue fracture analysis of wire rope for electric windows lifter

电动门窗升降器用钢丝绳在使用过程中过早发生断丝。采用扫描电镜、能谱仪对断裂钢丝进行失效分析,并进行疲劳模拟试验。研究表明:钢丝绳在电动升降器上整体发生断裂属于宏观高应力低周弯曲疲劳断裂,弯曲的结构来自于结构组成件上的局部弯曲,弯曲载荷相对于拉伸载荷在应力分布上具有极大不均匀性,会大幅度提高局部的工作应力,引发相关的疲劳开裂。给出预防措施:(1)在安装过程中,避免电动升降器钢丝绳承受弯曲载荷、各股受力不均匀;(2)钢丝绳在铆接头时避免产生严重的弯曲变形或铆接头内孔端头和滑板卡槽处变形;(3)钢丝绳和电动门窗升降器组成件在生产运输过程中避免碰撞、挤压、磨损。

Wire in rope for electric windows lifter broke early in service. Broken steel wire was failure analyzed by adop- ting SEM, EDS, and fatigue simulation was done. Results show that wire rope broke wholly in electric lifter belongs to mac- ro high stress low cycle fatigue bending, bending structure is from local bending of structure component, bending load has great inhomogeneity in stress distribution corresponding to tensile load, it will increase local working stress greatly, cause relative fatigue fracture. Preventing measures are as follows ： （ 1 ） in installation process, to prevent wire rope for electric lifter under bending load, each strand under stress uneven, （2） to avoid serious bending deformation when wire rope is riveted joint or deformation between inner hole end of invert joint and slide card slot, （ 3 ） to avoid collision, extrusion and wearing between wire rope and electric windows lifter component in production and transportation process.