| The research is supported by the NSFC'S (National Natural Science Foundation of China's) Funding: Smart Concrete and its Structure. (Program No: 50238040).The Smart Fiber refers the textile fiber which can sense environmental variation or stimulates, such as the machinery, the heat, chemistry, the light, the humidity, the electricity and magnetism and so on, and makes the response. The sensor is nervous system which detects the signal caused by the environmental variation or stimulates and is the key part of intelligent fiber.Among the fiber sensor, the optical fiber sensor is most widely applicable. The optical fiber technology has the function of signal detection and the transmission at the same time. It is widely applicable in the fields of intelligent highway, cement structure, intelligent construction, bridge, airplane outer covering and so on. The optical fiber sensor can detect the strain, the temperature, the displacement, the chemical substance density, the acceleration, the pressure, the electric current, the magnetic field and some other signals. And until now it is the most mature fiber sensor.When we use the optical fiber sensor to carry on the strain-gauging, the optical fiber axial strain response is used mostly, and the ideal situation should that the optical fiber responds slowly to the lateral strain. This article obtains from the optical fiber crosswise effect, and theoretically has developed from the experiment to the optical fiber sensor strain-gauging, the seal as well as the sign grades certain questions the research.1. The experiments have confirmed the existence of the optical fiber crosswise effect. A test installation which can produce the unidirectional strain field is designed. And therefore the change of the Bragg wave length is studied when the optical fiber diffraction grating only receives the lateral strain. And the results are compared with the axial strain response of the optical fiber diffraction grating. Results show that the lateral strain response of the optical fiber diffraction grating lateral strain response exits.2. Theoretically the error correction formula caused by the crosswise effect of the optical fiber is deduced. Combining material mechanics with the optical fiber diffraction grating strain response formula, the error correction formula of the optical fiber crosswise effect is obtained, and through the experimental, the influence of the optical fiber sensor installment position and the wiring error on the strain-gauging result has been studied and discussed .3. One kind of fiber sensor packaged by aluminum sheet has been manufactured, and through experimental the strain and temperature response characteristics are studied. The manufacturing optical fiber sensor is packaged by the aluminum sheet and the resin, and is stretched on certain experimental situation. Also the temperature test of the sensor has been carried on in the water bath, and its temperature response characteristic has been studied. One kind of fiber sensor packaged by steel pipe has been manufactured, and the temperature response characteristic has been studied. Theresults indicate that the sensor can better remove the interference of the strain better.4. Unifying one kind of the strain calibrations in two-dimensional optical fiber sensor, we have studied some questions which must be paid attention to in the strain calibration of the optical fiber sensor. Using different methods to carry on the strain calibrations in the two-dimensional optical fiber sensor, the different results are obtained. If we wants to obtain relatively accurate results of calibration, the calibration environment must be same or close to the actual survey environment. Using high-precision materials testing machines for the naked FBQ with numerous raster contingency — wavelength response curve. |
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