为评定某坦克扭力轴的现预扭处理工艺,用弹塑性有限元分析方法,模拟了扭力轴的预扭过程及极限加载过程．给出了预扭至最大角度、预扭释放后自由态、工作扭转至最大角度3种状态下轴体内的应力分布．结果表明,预扭后扭力轴弹性工作应力范围得到极大扩展,其主要原因在于预扭塑变形成的表面残余应力．扭力轴目前所采用的预扭强化工艺远没有发挥出材料的最大潜能． In order to evaluate the pre-twisting process of a torsion shaft of a tank, the pre-twisting process and the ultimate loading process of the torsion shaft were simulated by the elasto-plastic finite element analysis method. The stress distribution in the shaft body under the three states of pre-twisting to the maximum angle, the free state after the release of pre-twisting and the maximum angle of work are given. The results show that the elastic working stress range of torsion shaft after pre-twisting has been greatly expanded, mainly due to surface residual stress caused by pre-twisting plastic deformation. The torsional shaft is currently used in the pre-twist reinforcement technology far from playing the maximum potential of the material.