采用数值仿真和实验相结合的方法，研究振动环境中螺纹联接松动过程的动力学响应特性，寻求能提前预警螺纹联接失效的特征量。首先定性地分析了螺纹联接松动的变化过程，建立了高度简化的螺纹联接动力学模型；通过数值仿真和实验相结合的方法验证了定性分析和简化模型的正确性；最后通过对大量实验数据的分析，筛选出谐波失真度作为螺纹联接失效的预警指标。实验分析表明谐波失真度不论是简谐激励还是随机激励都能较好地识别螺纹联接的临近松动状态。

By numerical simulation and experimental, the dynamic response characteristics of unintentional unscrewing of threaded connection under vibration condition was researched. Features values of joints failure early-warning was found out. Firstly, qualitative analysis of the unintentional unscrewing process was preceded. Subsequently, a simplified dynamic model of the screw joint was built and verified. Finally, by analysis of experimental data, the THD was put forward as a better early-warning indicator. The results showed that the THD was a better early-warning indicator whether sinusoidal excitation or frequency bandlimited random excitation