裂缝损伤的光纤Bragg光栅传感检测与应变片检测对比研究

Comparison Research of Fiber Bragg Grating Sensors and Strain Gauges in Crack Detection

为测试光纤B ragg光栅(FBG)传感器用于结构裂缝损伤检测的可靠性,利用FBG裂缝传感器与应变片传感器同时检测钢-砼组合桥面板模型砼顶裂缝损伤。模型试验经历了静载、疲劳和破坏3个阶段。试验表明:在未发生裂缝损伤的静载和疲劳阶段,两种方法测试结果一致。在破坏阶段,模型各处相继出现裂缝损伤。利用FBG传感器测得经历3×106次疲劳试验后,钢-砼组合模型发生裂缝损伤的临界应变值,之后随着荷载的增加,FBG传感器继续追踪损伤的发展,直至破坏完成,显示了裂缝损伤发生发展的全过程,这是传统电测应变片传感器无法做到的。与传统电测方式相比,FBG传感器显示了高灵敏度,高精度,高可靠性和测试范围大等优点,尤其对于损伤发生发展全过程的检测,具有较大的优越性。

Crack monitoring of steel-concrete composite structures using FBG sensors and strain gauges was investigated with model test to detect the reliability of FBG sensors. The model endured three periods ：dead load test, fatigue test and destructive test. No crack occurred during the first two periods. The data measured by the FBG sensors and strain gauges were consistent. Results showed that FBG sensor can measure and trace the development of cracks, and compared to traditional electric methods, FBG sensor is more sensitive and reliable.