中文摘要：

针对实际工程结构中容易出现的螺栓联接松动问题进行了研究.采用Greenwood和Williamson模型和时间反演原理对聚焦信号幅值与螺栓预紧力的关系进行理论推导,得出两者成单调增函数关系;并据此提出一种基于时间反演法的螺栓健康监测方法.建立实验装置,进行实验研究.实验结果表明,聚焦信号幅值与螺栓预紧力的关系曲线近似于对数函数关系;接触界面粗糙度越大,聚焦信号幅值越快趋于稳定;时间反演法具有良好的自适应聚焦效果,能有效提高信号信噪比,在螺栓健康监测方面具有很好的应用前景.

英文摘要：

Bolt health monitoring is investigated for the bolt looseness in engineering structures.Greenwood ＆ Williamson contact model and time reversal theory are adopted for the relation derivation focusing signal and bolt pre-tightening force and get a monotone increasing relationship in result.A bolt health monitoring method based on time reversal is proposed.The experiment device is set up and serials experiments were carried out.Experimental results show that the relation curve between focus signal amplitude and bolt pre-tightening force is similar to a logarithmic function curve.The greater the roughness is,the faster focus signal amplitude inceases to a stable value.Time reversal method has a good self-focusing effect and can greatly improve the signal to noise ratio so as to have a good application prospect in bolt health monitoring field.