Fiber Bragg Grating Sensing Technology And Application In Bridge Crane Safety Assessment

Bridge crane is used to carry the material on the workshop, warehouse and yard. Its bridge is layed on the both sides of elevated rail and works longitudinally. It can fully take advantage of the space under below the bridge, without influenceing by the ground equipment. Bridge crane is currently the most widely used, the largest number of hoisting equipment. Bridge crane structure is complex, and its structure contains a large number of risk factors, too long time working will lead to the damage accumulation. Coupled with the long-term overload of work, the safety accident has become increasingly frequent. Crane structure health monitoring and life evaluation is the an important method for the safety evaluation of crane in service. The strain is an important reaction parameters of structure, and the long-term stability of stress and strain monitoring is an important part of crane safety evaluation system. By conparing a variety of strain measurement method and combined the actual construction case,the technical scheme of Crane safety evaluation system by Fiber Bragg grating strain monitoring was raised. The Strain data collected by FBG Sensing system was used to evaluate the security of the bridge crane. The specific work includes:(1)By conparing the working principle and characteristics of several strain measurement methods, the FBG strain detection was more confit than resistance strain measurement to monitor the strain of large structure inspection. By tensiling the standard workpiece with FBG sensors and Resistance strain gauge, Analying long-term measurement reliability and ability to resist interference of two kinds of strain measurement method, the conclusion was validated that Fiber Bragg grating method had better long-term reliability and anti-interference ability than Resistance strain measurement method.(2)A contrast experiment was designed by the characteristics of the equal strength beam. The Fiber Bragg grating strain measurement system performance at home and abroad was tested by the experiment. The conclusion was that the reliability and accuracy of the domestic FBG strain measurement system was below Foreign FBG strain measurement system. But the cost of the former was less, and it was aslo meet the requirements of crane stress strain monitoring accuracy.(3)With steel metallurgy bridge crane as the research object, the FBG sensors wassetting on the structure where the equipment would be damaged to monitor the s Structural strain of bridge crane. The strain date of FBG system was transferred to the cloud platform with the GPRS wireless transmission technology. The technical scheme of bridge crane safety assessment and implementation scheme of fiber Bragg grating sensor field was introduced. The accuracy of Fiber Bragg grating strain measuring system on the bridge crane health monitoring was validated. It provided data support to the life assessment of the bridge crane. By analysing the strain data of the FBG sensing system, the structural damage and service life of the bridge crane was confirmed.