Detection of Load Loss by Using a New Bolt Sensor

A new design of bolt sensor is proposed for real time detection of stress relaxation in bolted connections. Full bridge strain-gage circuit is installed in normal bolt and changes in the voltage signal are detected when the bolt is subjected to clamp load loss. The experimental and analytical results are presented and discussed. The proposed bolt sensor sensitivity is defined by series connection with high precision force sensor. The bolt load can be directly measured, and the method is successful in detecting the load loss both in the static and dynamic environments.