钢-混凝土组合桥面板模型混凝土顶裂缝损伤全过程检测

利用光纤Bragg光栅(FBG)传感器与电阻应变片同时监测,完成了钢-混凝土组合桥面板模型混凝土顶裂缝损伤检测。模型试验经历了静载、疲劳(300万次)和破坏3个阶段。测试结果表明无纵向承载裂缝出现时,FBG传感器测得相应位置的应变值。在破坏阶段,传感器布控区域相继出现裂缝损伤。利用FBG传感器测得了经历300万次疲劳循环后钢-混凝土组合桥面板模型混凝土顶发生裂缝损伤的临界应变值并追踪裂缝损伤的发展。与传统电测方式相比,FBG传感器显示了灵敏度高、精度高、测试范围大等优点。

Full-Process Test of Cracking Damages in Top of Concrete of Steel and Concrete Composite Deck Slab Model

The test of cracking damages in top of concrete of the steel and concrete composite deck slab model is completed by simultaneous monitoring of both the optic fiber Bragg grating(FBG) sensors and electric resistance strain gauges.The test of the model goes through three stages of static load,fatigue load(3 million cycles) and failure load.The results of the test show that when no longitudinal cracks occur,the strain values at corresponding locations are measured by the FBG sensors.At the stage of the failure,the cracking damages appear successively in the location areas of the sensors.The FBG sensors are also used for measuring the critical strain values and for tracing the development process of the cracking damages in the top of the concrete of the deck slab model that undergoes fatigue load test of 3 million cycles.Compared to the conventional electric measurement methods,the FBG sensors demonstrate that they have advantages of good sensitivity,high precision and wide measurement range.