水工建筑物渗压／应变光纤传感及其准分布式监测系统

A novel FBG (fiber Bragg grating) seepage pressure/strain sensor with all-glass packaging was presented and trial-produced for first time to be used in the quasi-distributed monitoring system with high sensitivity and long-term reliability for hydraulic buildings. The all-glass package casing is of drum-type in shape with shell thickness of 2-5mm and drmp-surface radius of 10-30mm and the watertight as well as loading tests have been carried out with the maximum water head of 200m. A FBG fit technique of "tight fixing with platinum wire forming" was developed. So the sticking is avoided and thereby the difficult problems induced by the aging, creep and low modulus of bonding compound used in metallic package. Hunce, the accuracy, sensitivity, reliability and durability of the FBG sersors have a decided advantage over ones with metallic pachaging.Presented was the nonlinear finite element analysis method of the fiberoptic-concrete complex and FBG sensor structural complex. The numerical simulation of the micro-mechanics and behaviors of the interfaces within these both complexes were carried out and the concept of attenuation of transducssion of strain within the elastic field was drawn from the FEM computation results. The method and the concept provide theoretical guidance as well as designing and computational method to package casing..A novel reflective seepage pressure sensor was analyzed, tested and trail-produced. The position and dynamic range (100μm) of optimum micro- displacement region with perfect linearity have been found out. The investigation reveals that the reflective coefficient of polished silver plating menbrane is biggest amoug 3 reflective menbranes tested. Its measured valus is 0.7..

提出渗压混凝土应变光纤传感的新型转换机制及其专用封装壳，基于激光直写技术研制光纤布拉格光栅以及FP扫描滤光器，以构成灵敏、长期稳定可靠的准分布式检测系统，具有测温、测应变全过程功能。完成理论分析与优化、精细加工、室内和现场试验。这会形成新生长点，推进大坝观测高科技的发展，对大地坝安全检查和水工科技有重要应用前景和学术价值。