FBG传感器在碾压仿真混凝土大坝模型实验中的应用

Experimental study on models of artificial roller compacted concrete dam by using FBG sensor

光纤光栅传感器(FBG)具有抗电磁干扰、结构简单、测量精度高、长期稳定性好,可以实现实时、在线监测等优点,在传感器领域中得到了广泛的应用。对自行开发的管式光纤光栅应变传感器进行了混凝土梁纯弯标定实验;利用光纤光栅传感器检测了混凝土结构内部的应变变化;应用该种传感器,对在白噪声、正弦波、随机波三种动力荷载作用下碾压仿真混凝土大坝坝段模型结构各个工况下的应变进行分析。结果表明:自行开发的管式光纤光栅传感器应变测量值与电阻应变片测量值符合很好;成功监测了碾压仿真混凝土大坝坝段模型在动荷载作用下的弹性应变和启裂应变,为大坝结构在地震作用下的健康状况分析提供可靠依据。

Optical fiber sensors have received increasing attention in the fields of civil engineering for their superior ability of explosion proof, immunity to electromagnetic interference and high accuracy, especially fitting for measurement applications in harsh environment. Three FBG strain sensors, which was packaged in a 1.2mm stainless steel tube by epoxy resin, were applied in the vibration experiment of an artificial roller compacted concrete dam model. The strain analysis was carried out for different working conditions such as noise, sine and random waves. The strain variations of two different sections of the dam model were monitored successfully in elastic and cracking stage induced by the action of dynamic load. The results show that the strains measured from tube-packaged Fiber Bragg Grating sensor and strain gauges are agreed each other; embedded FBG sensors can monitor possible fatigue and breakage damages of the structure conveniently, it is supplied reliable proof for health analysis of the dam structure under the action of earthquakes.