A tailless FBG smart bolt with good performance

A novel type of tailless FBG smart bolt with good performance is developed. Owe to the innovative design of an integrated FBG sensor comprising a strain measured FBG and a temperature-compensated FBG, the tailless FBG smart bolt serves the purpose of torque monitoring or bolt looseness monitoring. We use a theoretical approach to establish the linear correlation between the applied torque and the central wavelength of the tailless FBG smart bolt. Additionally, a newly designed M24 bolt with a nominal strength has been integrated as a crucial component of the tailless FBG smart bolt. To enable the experimental study, the tailless FBG smart bolt is newly designed, fabricated and tested. The experimental results show a strong linear correlation between the applied torque and the central wavelength of the tailless FBG smart bolt, showing good agreement with the theory.