为了适应矿井、大坝对渗压监测的需要, 提出一种活塞和菱形传压结构相结合的光纤布喇格光栅渗压传感器, 活塞把测试压力传递到菱形传压结构, 菱形传压结构拉动其上下对称连接的弹性钢片, 导致粘贴在弹性钢片上的光纤布喇格光栅中心波长产生变化.利用有限元方法在500 kPa的测试环境中对顶角分别为90°、110°、130°、150°情况下菱形传压结构的应力特性进行分析, 根据仿真参量研制了渗压传感器, 并对该传感器进行了压力标定试验和温度补偿试验.实验结果表明: 传感器对渗压的灵敏度为2.04 nm/MPa, 拟合度为0.997, 重复性为0.9%, 两个测压光栅温度灵敏度分别为0.023 33 nm/℃、0.021 68 nm/℃, 温补光栅为0.009 916 nm/℃.

In order to adapt to the seepage pressure monitoring′s need of the mine and the dam,a kind of fiber Bragg grating seepage pressure sensor based on the combination of the piston and the diamond structure was proposed. The piston passes the test pressure to the diamond structure and the diamond structure pulls elastic steel sheet, leading the center wavelength of the fiber Bragg grating bonded on the elastic steel sheet to change. In the 500 kPa test environment, the stress characteristics of the diamond structure were analyzed by using the finite element method when the vertex angle was respectively 90°, 110°, 130° and 150°. According to the simulation parameters, the seepage pressure sensor was developed and pressure calibration test and temperature compensation test were carried out on the sensor. Experimental results show that, the sensitivity of the sensor to the seepage pressure is 2.04 nm/MPa、the fitting degree is 0.997 and the repeatability is 0.9%. The temperature sensitivity of pressure measuring grating is 0.023 33 nm/℃ and 0.021 68 nm/℃ respectively, and the temperature compensation grating is 0.009 916 nm/℃.