Identification method of bolt looseness of power tower based on laser vibration measurement technology and time inversion

The reliability of bolted connections is directly related to the safe operation of transmission lines. Therefore, this article proposes a tower bolt looseness identification method based on laser vibration measurement technology and time inversion. Calculate the bolt tightening force coefficient under different usage conditions to obtain the maximum static friction force between angle steels; Analyze the changes in tension, calculate the average and standard deviation of bolt tensile stress; Under laser vibration measurement technology and time inversion, stress distribution was obtained. Assuming the Poisson's ratio and elastic modulus of the power tower bolts, analyze the relationship between guided wave propagation speed and axial force coefficient, construct a nut locking structure, obtain the axial force coefficient of the power tower bolts, and complete the identification of power tower bolt looseness. The experimental results show that the accuracy of using this method to identify loose bolt samples is close to 100%. This method can provide more powerful guarantees for the safe operation of power towers.