螺旋倾斜式光纤光栅传感器监测钢绞线应变方法研究

Research on Monitoring Strain of Steel Strands with Fiber Bragg Grating Sensor Setting Spirally and Slantingly

设计了一种在钢绞线中心丝上设置螺旋倾斜凹槽,将光纤光栅(FBG,Fiber Bragg Grating)传感器封装于凹槽中的自感知钢绞线,以解决FBG传感器寿命低、量程小而无法监测大应变的问题。建立了FBG传感器监测应变与钢绞线应变之间的理论关系,以凹槽螺旋倾斜角度为变化参数,对FBG自感知钢绞线进行张拉试验,测定FBG传感器灵敏度的变化情况。试验结果表明:通过螺旋倾斜放置光纤光栅能有效降低FBG传感器的应变灵敏度,使其监测量程接近钢绞线的极限破断力,从而实现应用FBG传感器监测大应变的目的。

A helical sloping groove was designed on the center wire of steel strand and the fiber bragg grating(FBG)sensor was wrapped in self-sensing steel strand of grooves in order to solve such problem as low life and small range of FBG sensor,which makes it difficult to monitor large strain.The theoretical relationship between the strain of grating monitoring and the strain of steel strand was established,the tensile test of FBG self-sensing steel strand was carried out by taking the groove helical tilt angle as the changing parameters,and the sensitivity change of FBG sensor was measured.The test results show that placing fiber bragg grating spirally can effectively reduce the strain sensitivity of FBG sensor and make its monitoring range be close to ultimate breaking force of steel strand so that the purpose of monitoring large strain can be achieved with FBG sensor.