Experimental Study On Force State Monitoring Of Anchor Based On Fiber Bragg Grating

With the development of the coal mining industry,the safety issues in the mining process become more and more important.In order to reasonably design the supporting intensity of the roadway,monitoring the loading conditions of the bolts in use becomes an important research topic.By analyzing the load condition of the anchor rod,we can understand the situation of the surrounding rock of the anchor rod.Designing and improving the support scheme of the roadway can play a significant role in keeping the roadway open and the roadway surrounding rock stable and avoiding coal mine safety accidents.For the monitoring of bolt load,this paper uses FBG as an intelligent sensing element to study its sensing theory and characteristics.The layout of the sensor is designed.Through theoretical analysis and experimental verification,it is proved that the FBG sensor can be effectively used to calculate the radial and axial load of the anchor bolt by using this arrangement method to arrange the FBG sensor on the anchor rod.First of all,this paper analyzes and studies the arrangement of FBG sensors on the bolts,analyzes which layout method can effectively obtain the requireddata,and then uses the obtained data to establish a reasonable mechanical model and then performs mathematical calculations.Derive a reasonable calculation formula.After theoretical analysis of the sensing theory and characteristics of FBG,the feasibility and reliability of FBG as a strain sensor is proved theoretically,and its accuracy is more suitable for radial load measurement.Secondly,using the simulation experiment,the FBG force bolt was designed and manufactured,and the radial load of the anchor bolt was simulated in the laboratory.The radial load information applied to the anchor rod in the experiment was successfully obtained by using the axial strain data of each measuring point position of the anchor rod obtained by using the FBG sensor.And by actually measuring the deflection data of several positions of the anchor bolt and comparing the results measured by the FBG,it is concluded that it can accurately measure.Finally,ANSYS finite element numerical simulation software was used to simulate the situation where the bolt was subjected to another kind of radial load.Using the calculation function of the simulation software,directly extract the axial strain data of the anchor with the same position as the FBG sensor in the experiment.Then use these data to calculate the radial load of the bolt.The result is more accurate than the experiment,and it is further proved that the FBG force bolt produced by the arrangement of the sensor can accurately monitor the anchor rod within a certain range.Radial load specific conditions.