The self-loosening failure of bolt connection will bring a series of problems. Sakai first proposed the self-loosening theory of fixed nut and free bolt head under rotational vibration. Based on this theory, this paper proposed a more extensive self-loosening theoretical criterion under the boundary condition of free nut and free bolt head under rotational vibration. The theoretical analysis shows that there are two forms of self-loosening failure under the new boundary conditions, which are the bolt head self-loosening failure and the nut self-loosening failure. Combining with the finite element analysis, it is shown that the proposed self-loosening theory is in good agreement with the simulation results. It is concluded that the self-loosening mechanism of the first case is caused by the complete slipping of the bolt head bearing surface and the thread surface. In the second case, the self-loosening is caused by the complete slipping of the thread surface and nut bearing surface. Local slipping does not cause loosening failure, which is different from the loosening mechanism under transverse vibration. Finally, the influence of several factors on bolt loosening is studied. The results show that the vibration amplitude and initial preload have great influence on bolt loosening, while the vibration frequency has little effect on bolt loosening.

螺栓连接的自松动故障会带来一系列问题。酒井首先提出了旋转振动下固定螺母和自由螺栓头的自松动理论。在此理论的基础上，提出了在自由螺母和自由螺栓头在旋转振动条件下的边界条件下更宽泛的自松动理论准则。理论分析表明，在新的边界条件下，自松动失效有两种形式，即螺栓头自松动失效和螺母自松动失效。结合有限元分析表明，所提出的自松动理论与仿真结果吻合良好。可以得出结论，第一种情况的自松动机制是由螺栓头轴承表面和螺纹表面的完全滑动引起的。在第二种情况下，自松动是由螺纹表面和螺母轴承表面的完全滑动引起的。局部打滑不会引起松动失败，这与横向振动下的松动机制不同。最后，研究了几个因素对螺栓松动的影响。结果表明，振动幅值和初始预紧力对螺栓的松动影响很大，而振动频率对螺栓的松动影响很小。这与横向振动下的松动机制不同。最后，研究了几个因素对螺栓松动的影响。结果表明，振动幅值和初始预紧力对螺栓的松动影响很大，而振动频率对螺栓的松动影响很小。这与横向振动下的松动机制不同。最后，研究了几个因素对螺栓松动的影响。结果表明，振动幅值和初始预紧力对螺栓的松动影响很大，而振动频率对螺栓的松动影响很小。