Bolt Force Monitoring Device by Fringes Method

An optical monitoring method is proposed for the force monitoring of mine-used anchor. According to the linear relationship between the stress and strain of the optical film, the change of the optical film dip under the light source will cause the change of the number of interference fringes. We determine the safety status of the anchor with the number of interference fringes. Through ANSYS finite element analysis and MATLAB simulation analysis, the number of interference fringes changes from 0 to 10 when the load of monitoring device is from 0 to 18.2 t. Interference fringes visibility and suitable observation distance were analyzed. The results show that the monitoring device is feasible.