基于压电主动传感方式的螺栓松动检测实验研究*

摘要

For the measurement of bolt axial force and detection of bolt loosening,the ultrasonic method is studied using the piezoelectric active sensing technique. When the ultrasonic wave generated by a piezoelectric patch propagates across the interface of the components jointed by the bolt,only part of the ultrasonic wave energy passes through it. The transmitted wave energy depends on the true contact area which is decided by the bolt pretension ac-cording to the Classical Hertz contact theory. By measuring the received energy with another piezoelectric patch on the other side of the connected components, the bolt pretension or bolt connection status can be detected. The experiment device is set up and serials experiments were carried out. The experiment results show that the wave energy propagated across the interface has good correlation with the torque level. This method has potential application for the monitoring of bolt loosening in-site.%针对螺栓联接结构中螺栓易松动而引发事故的情况，进行了压电主动传感方式的螺栓松动检测研究。采用压电材料激发超声波，根据透射波通过螺栓联接界面时，透射波携带的能量与界面间实际接触面积相关，而界面实际接触面积与界面压力(即螺栓作用力)成一定关系，通过测量透射波的能量确定螺栓的松紧程度。建立了实验装置，进行了实验研究。实验结果显示，作为传感器的压电材料所接收到的超声波能量与螺栓紧固力具有较好相关性，该方法可作为螺栓联接结构健康监测的一种新方法。