Abstract: Aiming at the influence of FBG temperature on cross sensitivity, a water bath circulating device of intelligent prestressed steel strand was designed and manufactured. The water bath cycling test was carried out on steel strand under stress-free condition, and the temperature compensation model of intelligent prestressed steel strand was studied. The water bath cycling test of intelligent prestressing steel strand in stress state was carried out. The wavelength test results of the optical fiber sensor modified by the temperature compensation model were obtained and compared with the test results of the vibrating string pressure sensor, which verified the validity of the temperature compensation model of the intelligent prestressed steel strand. The research results show that the temperature sensing coefficient of FBG intelligent steel strand is 0.0226 nm/℃, which is about 2.3 times of that of bare fiber. The expression of the relationship between the change of optical fiber wavelength and the change of temperature and the expression of the relationship between the change of optical fiber wavelength and the change of tensile force are obtained. The test results of intelligent prestressing steel strand after temperature correction are consistent with those of vibrating string pressure sensor, and the correlation coefficient is 0.97.

Key words: bridge engineering, intelligent steel strand, fiber bragg grating (FBG), water bath cycling test, optical fiber wavelength

摘要： 针对光纤光栅的温度对应变交叉敏感的影响问题，设计及加工了智能预应力钢绞线的水浴循环装置，对无应力状态的钢绞线进行水浴循环试验，研究智能预应力钢绞线的温度补偿模型；对有应力状态的智能预应力钢绞线进行水浴循环试验，基于得到温度补偿模型修正光纤传感器的波长测试结果，并与振弦式压力传感器测试结果进行对比分析，验证了智能预应力钢绞线的温度补偿模型的有效性。研究结果表明：光纤光栅智能钢绞线温度传感系数为0.022 6 nm/℃约为裸光纤的2.3 倍，得出光纤波长变化量与温度变化的关系表达式及光纤波长变化量与张拉力变化的关系表达式；温度修正后的智能预应力钢绞线测试结果与振弦式压力传感器测试结果一致，相关系数达到0.97。

关键词: 桥梁工程, 智能钢绞线, 光纤光栅, 水浴循环试验, 光纤波长