A passive and wireless smart washer for monitoring bolt pretightening force

Abstract For the improvement of the safe operation of specific structures, it is crucial to monitor the bolt pretightening force. Conventional approaches frequently call for complicated systems that are challenging to install and cumbersome to operate in order to produce precise measurements. It is suggested that a passive wireless smart washer be used to track bolt pretightening force. The smart washer is installed together with the bolts, and a handheld terminal can be used at any moment to detect the tightening force of many bolts. Pretightening force and strain sensing are obtained by the washer structure, and the circuit in the washer obtains energy via a printed antenna to start the acquisition of a signal based on Near Field Communication technology. The data is then sent to the terminal for visualization and analysis. The prototype’s experimental findings demonstrate that the smart washer can keep track of the bolt’s pretightening force both during and after tightening.