回转支承构件牵引滚动接触应力解析

Contact stress anslysis of rotary-support component under tractive rolling contact

回转支承构件是重型机械的重要基础元件,其失效往往导致灾难性的设备事故和人身事故以及巨大的经济损失。及时、充分地了解回转支承构件牵引滚动接触应力分布特点,对于保证整机安全生产和提高企业经济效益具有非常重要的意义。本文将回转支承构件接触模型简化为轴线平行的圆柱体二维平面应变模型,从接触力学理论中McEwen关于轴线平行的圆柱体二维法向接触理论出发,重点讨论牵引滚动与常规法向接触状态的切向分布力的相同点和不同点,从而推导出牵引滚动接触状态下接触区应力场各应力分量解析式,将McEw-en法向理论公式推广到法、切向复合分布力综合作用下。在此基础上,探讨了表面拉应力与摩擦系数的关系,摩擦系数越大则表面拉应力水平越高。最后,运用材料力学二向应力状态受力分析方法,计算了接触应力场最大剪应力位置、大小和方向角与深度的关系,发现与无表面摩擦情况相比,最大主剪应力发生位置变浅,幅值反而变小。

Rotary support components are important essential unit of heavy--duty machinery, their failure always result in equipment accident, human injury and substantial economic losses. We must find out the distributed characteristic of traction rolling contact stress of rotary support components in time and adequately so as to ensure safety in production of complete appliance and economic benefits increase of business. In this paper, the rotary support components＇ contact model has been simplified to 2D plane strain model of paralleled cylinder firstly, then the 2D normal contact theory of paralleled cylinder by McEwen from contact mechanics theory has been used as starting point, emphasis discussing the same and different points of tangential friction force between traction rolling contact and general normal contact, the analytic formula of stress components in contact stress filed under traction rolling contact has been deduced, and the McEwen normal theoretical formula has been extended to compound situation with normal and tangential force. Based on it, the maximum, position and direction angle of the primary shear stress have been calculated by biaxial stress analysis method. The results indicated that the position of maximum primary shear stress under traction rolling contact was lower than frictionless contact, and the maximum decreased.