应用光纤光栅传感技术监测铁路钢桥螺栓断裂脱落的模型试验研究

为控制铁路钢桥高强度螺栓断裂脱落造成的铁路运营安全隐患,提出了一种基于光纤光栅传感技术的螺栓断裂脱落监测方法。从螺栓断裂脱落监测和防护2方面入手,设计了针对联结节点螺栓群的防护装置,避免断裂螺栓脱落侵入线路。以断裂螺栓部件冲击防护装置产生的应变作为脱落损伤标识量,利用布置于钢桁梁上的光纤光栅传感器测量应变,根据应变的变化确定螺栓断裂脱落情况。通过制作钢桥横联联结节点模型开展了螺栓断裂脱落监测试验,试验结果表明,该方法能够有效监测螺栓断裂脱落的时间、数量及位置信息,初步验证了应用于螺栓断裂脱落监测的可行性,为工程应用奠定了基础。

Model Test on Monitoring for Bolts Fracture and Dropping in Railway Steel Bridge Based on Fiber Bragg Grating Sensor Technology

In order to control the hidden danger of railway operation caused by high strength bolts fracture and dropping in railway steel bridge,a monitoring method of bolt fracture and dropping based on fiber Bragg grating was proposed.Starting from the monitoring and protection of bolt fracture and dropping,the protection device for bolt group of connection node was designed to avoid bolt fracture and invading the railway.The strain produced by the impact of the fracture bolt on the protective device was taken as the signature for damage detection.The strain was measured by the fiber Bragg grating sensor arranged on the steel truss girder,and the condition of bolt fracture and dropping was determined according to the change of the strain.Through making the model of transverse joint of steel bridge,the monitoring test of bolt fracture and dropping was carried out.The test results show that the method can effectively monitor the time,quantity and position information of bolt fracture and dropping,preliminarily verify the feasibility of applying it to bolt fracture and dropping monitoring,and lay a foundation for engineering application.