A low-power wireless sensing device for remote inspection of bolted joints

Abstract

A new bolted-joint monitoring system is presented. This system consists of structural joint members equipped with piezoelectric (PZT) sensing elements and a wireless impedance device for data acquisition and communication. PZT enhanced washers are used to continuously monitor the condition of the joint by monitoring its dynamic characteristics. The mechanical impedance matching between the PZT enhanced devices and the joint connections is used as a key feature to monitor the preload changes and to prevent further failure. The dynamic response is readily measured using the electromechanical coupling property of the PZT patch, in which its electrical impedance is directly coupled with the mechanical impedance of the structure. A new miniaturized and portable impedance measuring device is implemented for the practical implementation of the proposed method. The proposed system can be used for the remote and rapid inspection of bolt tension and connection damage. Both theoretical modelling and experimental verification are presented to demonstrate the effectiveness of the proposed concept.