Anchoring Screws Health Detecting and Measures to Prevent Fracture

Chongqing Light Rail is one of the main transport facilities. Anchoring screws are the important parts to connect Light-Rail's girders and piers. Their health directly affects the safety of Light-Rail operations. This paper describes a health monitoring system which uses NDT technology to test the Light-Rail anchoring screws in service. It can detect the state and internal defects of anchoring screws. Based on these test results, the service capacities of the anchoring screws are valuated. When the system were detecting them, a few anchoring screws were found of breakage failures, and afterwards these discoveries were confirmed by artificial examination. In order to further investigate the reasons for breaking the anchoring screws and eliminate safety hazards, we built ANSYS finite element models of anchoring screws and girders of the Light-Rail and calculated their dynamic responses under various operating conditions. For these faulty anchoring screws, we made the metallographic tests. Through computational analysis and metallographic analysis, we found the reasons of fracture, and proposed measures to prevent breakage.


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