基于弯曲伸张结构的光纤光栅传感研究

Fiber-optical grating sensing based on flextensional member

以民用工程结构如桥梁、大坝、高层建筑的健康检测为背景,采用光纤光栅传感器实现对结构性能的实时监测和诊断,及时发现结构的损伤以评估结构的安全性.提出了一种可用于光纤光栅传感的新型弯曲伸张弹性敏感结构,可实现对压力、应变以及加速度的准确测量.对该结构弯梁腹部处的应变进行了理论分析和实验验证,结果表明弯梁腹部处各点的应变与该弯曲伸张结构在竖直方向上所受压力、应变以及加速度大小成线性关系.其最大的优点是同样灵敏度下体积小,在井下等横向尺寸受限、又要测量纵向加速度的情况下,梁式传感结构很可能无法使用,该新型弯曲伸张型弹性敏感结构可作为弹性元件用于光纤光栅压力、应变、称重以及加速度传感器的设计.

Based on the structure health monitoring of civil engineering structure such as bridges, dams, high-rise building, the fiber Bragg grating sensor is used to achieve the real-time monitoring and diagnosis of structural performance, in order to discovery the damage and to evaluate the safety of structure. Fiber-optical grating sensing based on flextensional member is proposed. The measuring of pressure, strain and acceleration can be realized. The strain of camber beam belly is analysed theoretically and verified experimentally. The strain of the camber beam belly is proportional to the pressure and acceleration in the vertical direction. Its biggest advantage is small size under the same sensitivity. The transverse dimensions is limited in well and the longitudinal acceleration needs to be measured, so beam based sensor structure are not likely to be used. Under the condition of measuring longitudinal acceleration sensor structure, beam pumping are not likely to be used. This new type of flextensional member elastic sensitive structure can serve as elastic element for the design of fiber bragg grating strain, weighing and pressure, and acceleration sensor.