根据目前大坝、隧道和煤矿等工程领域和模型试验中对渗压检测的特殊要求,设计并实现了一种新型的光纤布拉格光栅(FBG)渗压传感器,采用波纹膜片和对称拉杆机械结构通过改变光纤光栅的轴向应变实现渗压传感。利用有限元软件ANSYS分别对传感器膜片的压力特性和传感器外壳抗压特性进行了仿真设计和性能分析,提高了传感器的可靠性并缩短了设计周期。对该传感器进行了压力标定试验,得出该传感器在0-100 kPa的测量范围内,压力灵敏度达20 nm/MPa,比普通FBG提高了6683倍。迟滞特性和重复性试验表明迟滞为0.85%,且重复性好。

According to special requirement of seepage monitoring in engineering and model experiment of dams,tunnels and coal mines,a novel optical fiber Bragg grating (FBG) based seepage pressure sensor is designed and fabricated. A draw-bar structure and a corrugated diaphragm are adopted to change the axial strain of optical fiber grating. The diaphragm pressure characteristics and sensor′s shell resistance characteristics are simulated and analyzed by using the finite element software ANSYS respectively,which can shorten the design cycle and improve the reliability of the sensor. Calibration experiments show that the pressure sensitivity of the sensor is 20 nm/MPa in the range of 0-100 kPa,which is 6683 times higher than that of ordinary optical FBG. The hysteresis and repeatability experiments indicate that the hysteresis factor is 0.85% and the sensor has good reproducibility.