压力传感器冲压压力作用下温度结构效应的检测技术

传感器接壤的介质受到冲击压力作用时，温度会突然升高。冲击和温度会对传感器内部结构性能产生影响，引起测量值的严重偏差。用激波管法，快启阀门法和落锤冲击法因其各自固有的特点无法检测传感器的冲击温度结构效应。本文介绍用高精度，超高压，气动正阶跃压力发生器对传感器冲击温度效应的检测方法。     

FBG智能传感器及其在土木工程中的应用研究

光纤光栅传感器已经越来越得到土木工程界的认可,并应用到了实际工程.针对大型土木工程结构长期健康监测的变形监测需要,在光纤光栅传输理论的基础上,分析了光纤光栅应变与温度传感特性以及光纤光栅应变传感的温度补偿原理和方法;研制开发出满足工程应用的光纤光栅封装传感器、FRP-OFBG复合智能筋、光纤光栅智能拉索;此外,考虑传感器开发和工程应用的需要,研究了光纤光栅应变传感的界面传递机理和误差修正.最后,建立了光纤光栅智能监测系统,并成功地将光纤光栅传感器应用到实际桥梁结构的施工与运营监测.     

SnO2气体传感器的复阻抗谱研究

本文研究了静电喷雾高温分解工艺制备的ＳｎＯ２薄膜气体传感器在不同温度与气氛条件下的复阻抗谱，根据等效电路模型与复阻抗谱的变化，分析了电导调制机构与气敏机理，基于气体在晶界与表面吸附效应提出了气体敏感的物理化学模型．     

数字式与模拟式称重传感器的区别及应用

模拟式称重传感器基本上属于“手工制造”型，其性能会受到操作工的技能、情绪等人为因素的影响．此外模拟式称重传感器的零点温度、灵敏度温度、线性、滞后、蠕变等补偿方式和补偿工艺远远不够完善，多项补偿之间的相互作用．不可避免地产生残余误差，这样就限制了它的准确度和稳定性的进一步提高。     

新型光纤电流传感器的研制

光纤电流传感器运用Faraday效应,将光纤绕在电流母线上可以方便地测得电流母线中的电流,但光纤电流传感器的信号受环境振动、温度变化的影响严重,从而限制了其应用。本文从分析振动、温度变化的干扰机理出发,提出一种新型的在线校正方法来抑制干扰的影响,并进行了原理性实验。研究结果表明,用这种方法实现的光纤电流传感器在40～400A之间有良好的线性度和精度。     

汽车用压电传感器的现状

汽车用压电传感器的现状喜多彻１．汽车用传感器的现状在汽车中，作为测量对象的物理量与所用的传感方式和装置是多种多样的，测量对象中使用传感器数量最多的是位置，以下依次是温度、转动、加速度、压力。关于使用的装置（材料）方面，在６４个传感器中，有１８个是使用...     

用光纤传感器阵列测量动态变量

用光纤传感器阵列测量动态变量Ｊ．Ｎｉｅｗｉｓｃｈ等１．概述分布式光纤传感器或由光纤连接成的光传感器阵列，在大面积、多测量点的监视方面有很大的潜力。定位分辨率可用光时域反射计（ＯＴＤＲ）的原理来表达，这个方法最典型的用途为静态效应（仅随时间作慢变化的测...     

基于钹式换能器的振动加速度传感器温度特性研究

使用2-（0）-2连通型的金属．陶瓷压电复合材料作为敏感元件构成压电振动加速度传感器。研究了这种新型压电振动加速度传感器的输出电压的温度特性．将DS18820集成到传感器内部用于内部环境温度的测量。利用单片机对传感器零位输出电压进行记录，得到传感器零位电压温度特性曲线。采用了基于最小二乘原理的分段线性插值法，对其温度特性的非线性进行了有效地补偿。试验结果表明，经过温度补偿后，在20～80℃范围内，零点输出电压温度误差由原来的9．8％降到了0．8％。     

自组装壳聚糖接枝聚苯胺/葡萄糖氧化酶生物传感器的研究

合成了壳聚糖接枝聚苯胺，并采用静电自组装法制备了壳聚糖接枝聚苯胺／葡萄糖氧化酶生物传感器。讨论了温度、pH值、离子强度以及自组装膜层数对传感器电流响应的影响。制备的葡萄糖生物传感器检测范围为0．5mmol／L～16mmol／L，电流响应时间仅为5．2s。     

基于平面环形微腔结构的超高灵敏度位移传感器的研究

以平面环形微腔结构为核心器件,基于量子力学的隧道效应和“参量振荡不稳定”效应,结合理论计算及ANSYS和Beamprop仿真,设计出基于环形微腔结构的超高灵敏度位移传感器,特别是在1．55μm的谐振波下,对所设计的位移传感器进行了ANSYS力学仿真、Beamprop传输特性仿真以及输出特性数值模拟,论证了位移传感器的可行性,并为以后的实验奠定了基础。     

复合材料层间应变测试实验

复合材料受到应力作用层间会产生变形,应力过大层间会出现撕裂的现象。针对这一问题, 利用光纤法珀应变传感器与复合材料层间间隙尺寸相当的特点,将该传感器置入复合材料层间,在万能拉伸仪上进行复合材料应变测试实验。实验表明:利用光纤法珀应变传感器检测复合材料层间应变的方法是完全可行的。     

Fiber Optic Bend Sensor for In-Process Monitoring of Polymeric Composites

Wrinkles, porosity, delaminations and other defects introduced during the manufacturing processing can compromise mechanical performance of advanced composites. This paper describes a method of using fiber optic sensors for monitoring the formation of graphite fiber bending in real time during manufacturing process. Theoretical formulation of the sensor behavior and experimental results are presented. The response of the sensor to composite fiber bending is characterized. The application to analyzing the formation of wrinkles in compression molding of graphite/epoxy composites is demonstrated.     

1-3型水泥基压电复合材料传感器的性能

以 123型水泥基压电复合材料作为传感元件制备了水泥基压电复合材料传感器。研究了水泥基压电复合材料传感器的频率响应、 线性性能以及应用于混凝土后的传感性能。结果表明: 当加载频率小于 5 Hz时 , 所有载荷下传感器输出电压的幅值均增大 , 但当加载频率大于 5 Hz时 , 所有载荷下传感器输出电压的幅值几乎与输入载荷频率无关 ; 传感器的输出电压幅值和输入载荷幅值之间存在明显的线性关系。水泥基压电传感器在实际混凝土结构中具有良好的传感特性 , 其输出电压与复杂载荷、 随机载荷和脉冲载荷均呈现明显的一一对应关系 ,且与输入载荷基本同步 , 不存在滞后现象 , 试验输出电压值与理论输出电压值也非常吻合。该传感器非常适合于土木工程结构的健康监测。      

复合材料无损检测与光纤传感器

本文讨论了复合材料测试特点,介绍了光纤传感器原理及特点,重点讲述光纤传感器在复合材料无损测试中的应用。     

Simultaneous sensing of the strain and points of failure in composite beams with an embedded fiber optic Michelson sensor

A fiber optic Michelson sensor was embedded in composite beams to sense the internal strain and points of failure of the composite structures. The bending deformation and matrix cracking were investigated by four-point bending tests of cross-ply composite beams with the embedded fiber optic sensor. The failure points of composite beams were detected by using both a PZT sensor and a fiber optic sensor in order to investigate the fiber optic failure signals. The failure due to matrix cracks in a composite beam was confirmed by the edge replica method. The digital processing of the fiber optic signal was carried out to determine the strains and failure points of composite beams. The failure points were observed from the processed failure signal by high-pass filtering. The initial failure strain of the composite beam was measured and processed from the fiber optic strain signal after low-pass filtering.     

复合材料热压成型过程用光纤压力测试技术

针对复合材料热压过程的工艺特性,建立了光纤微弯传感压力测试系统,并对系统在复合材料成型过程的适用性进行了评价。结果发现,该系统适合应用于温度小于120℃、压力范围0.005~0.5 MPa的测试环境,具有较好的重复性和稳定性;光纤在调制器中的排布密度、测试环境温度及光纤微弯形变回弹对输出光功率有一定的影响。在以上研究基础上拟合并验证了测试系统载荷-光功率方程。      

Fabrication and Sensing Performance of Smart Composite Structures Using Optical Fibre Sensors

This paper determines the performance of Fibre Bragg Grating (FBG) sensors for strain sensing applications in carbon fibre composite materials. Carbon fibre laminates in either cross-plied or quasiisotropic stacking sequences were fabricated using T300/Hexcel 914 prepregs. The FBG optical sensors were either surface attached, or embedded within laminates. The sensor orientation was aligned either parallel or transverse to the adjacent carbon fibre layers. The composite structures with integrated FBG sensors were subjected to static tensile loading. A scanning fibre Fabry-Perot filter was used to monitor the reflected Bragg wavelengths. The optical sensor embedded between two 90° carbon fibre plies shows a high sensitivity to multi-site cracking formed in the transverse plies. The embedding in 90° plies seems to change the local stress distributions and to become a source of crack initiation. Efficient stress transfer from the host materials to the sensors is dependent upon incorporation methods, the thickness of the adhesive layers, and the location of the sensors.     

Sensitivity of embedded fibre optic Bragg grating sensors to disbonds in bonded composite ship joints

The potential application of embedded fibre optic Bragg grating strain sensors for the health monitoring of adhesively bonded composite ship joints is investigated in this paper. Bragg grating sensors were embedded at various locations along the interface of adhesively bonded glass-reinforced plastic composite joints with artificially introduced disbonds to assess their capability to detect bond-line damage under in-plane shear and through-thickness tension. Finite element (FE) models indicated that the presence of the disbond significantly altered the bond-line strain distribution under such loads. The embedded sensors successfully detected this effect, and the sensor measurements compared well to FE predictions. However, the experimental measurements of the magnitude of the strain at the tips of the disbonds showed significant variations, presumably due to its high sensitivity to defect edge conditions which could not be experimentally controlled with a high degree of repeatability. Both the FE models and the experimental results showed that the effect of disbond damage was localised, more so under in-plane shear than through-thickness tension. This would necessitate the use of an optimised sensor array and pattern recognition algorithm for the reliable detection of an arbitrary disbond.     

光纤缠绕式应变传感器

研究了一种可用于机敏复合材料与结构状态监测的本征型强度调制光纤应变传感器,它由两根以上多模光纤相互缠绕绞合形成。分析了该传感器的应变传感原理,得到其既能测量拉应变、又能测量压应变的结论。传感器对应变的响应具有良好的线性和重复性,灵敏度高,无迟滞现象。对植入碳纤维/环氧复合材料内的光纤缠绕型应变传感器的实验结果与理论分析一致,表明该传感器是适合于机敏复合材料与结构状态监测的较为理想的光纤传感器。     

声表面波压力传感器信号采集与处理

声表面波 (SAW)传感器能将被测量转换成容易检测的频率信号 ,即一种准数字信号的输出。针对 SAW压力传感器 (以 CSF- 1 0型 SAW压力传感器为对象 )的输出特点 ,利用等精度频率测量法测量输出频率 ,并用 Dallas的单线数字温度传感器 DS1 8B2 0测出现场温度 ,采用 BP神经网络对所得数据进行温度补偿后得到精确的被测压力值