Pull out tests of figer Bragg grating sensor fitted bolts
Abstract：A fiber Bragg grating (FBG) bolt monitoring system was designed and tested to pro- vide long term, continuous monitoring of stresses in the bolt. Stresses that exist in a coal mine tunnel were simulated in the laboratory using a Ф18 metal bolt and a pull out load of 76.44 kN. Three FBG sensors were installed along the bolt to measure strain. An additional sensor was installed at the end of the bolt to monitor the axial stress in the bolt. Three resistance strain gauges were also installed adjacent to the FBG sensors for comparison. The axial stresses and strains were recorded during a pull out test and subsequently analyzed. The results show that axial stresses measured by the FBG sensor at the end of the rod are consistent with both the re- sistance strain gauges and the other three FBG sensors. The strain transfer function for the FBG sensors along the bolt is 0. 879. The FBG sensor is easily installed at the end of the bolt and is reusable. This provides a maintenance advantage. This test method is reliable and effec- tive for real time monitoring of bolts.
Keywords：fiber Bragg grating sensingboltpullout testend-of-rod FBG sensor
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 719-724 )