光子学报, 2018, 47 (1): 0106002, 网络出版: 2018-01-30
FBG应变传感器应力疲劳极限传感寿命评估方法
Evaluation Method of Ultimate Sensing Life for Stress Fatigued FBG Strain Sensors
光纤光学 极限传感寿命 应力疲劳 光纤光栅 满度相对误差 等强度梁 Fiber optics Ultimate sensing life Stress fatigue Fiber Bragg grating Full scale relative error Equal strength beam
摘要
光纤光栅应变传感器在应力疲劳作用下不可避免地出现性能衰退, 为了评估其极限传感寿命, 从光纤光栅传感原理出发, 理论推导了应力疲劳作用引起的满度相对误差表达式, 以工业仪表精确度等级作为传感器的极限状态阈值, 提出了基于等强度梁的极限传感寿命测试方法.利用该方法评估了高桩码头结构健康监测应用环境中光纤光栅应变传感器的极限传感寿命, 以满度相对误差变化4%作为极限失效阈值, 对4支传感器进行了1.32亿应力疲劳实验.当疲劳至1.32亿次时, 2支传感器达到极限传感寿命, 1支传感器接近极限传感寿命, 即极限传感寿命约为1.32亿次.实验结果表明, 提出的方法能有效地测试不同结构健康监测需求下, 光纤光栅应变传感器的应力疲劳极限传感寿命.
Abstract
The performance degradation of fiber Bragg grating strain sensors is unavoidable under stress fatigue, in order to assess the ultimate sensing life of fiber Bragg grating sensors, the full scale relative error expression of stress fatigue effect is deduced from the principle of fiber Bragg grating, and the industrial instrument accuracy class is used as the limit state threshold of the sensor. And then a method based on the beam of constant strength is put forward to test the ultimate sensing life. The ultimate sensing life of fiber Bragg grating in high pile wharf structural health monitoring application is assessed by this method, the failure threshold of full scale relative error is set as 4%, 4 fiber Bragg grating sensors suffer from 132 million times alternate strain, when the fatigue number reach to 132 million times, 2 sensors reach the ultimate sensing life, 1 sensor proximity reach the limit. That is, the maximum sensing life is 132 million times. Experimental results show that the proposed method can effectively test the ultimate sensing life of stress fatigued fiber Bragg grating strain sensors in different structural health monitoring application.
舒岳阶, 吴俊, 周世良, 周远航. FBG应变传感器应力疲劳极限传感寿命评估方法[J]. 光子学报, 2018, 47(1): 0106002. SHU Yue-jie, WU Jun, ZHOU Shi-liang, ZHOU Yuan-hang. Evaluation Method of Ultimate Sensing Life for Stress Fatigued FBG Strain Sensors[J]. ACTA PHOTONICA SINICA, 2018, 47(1): 0106002.