Development of Smart Structure for Thermo-Insulating-FRP-Support-Structure by Using Optical Fiber Sensor

点击翻译按钮获取中文摘要

Since composite support structures applied to super conductivity coils are covered by structures for insulation, automatic health monitoring system is very important for the structures. The composite support structures for super conductivity coils are in strong variable magnetic fields. This causes that it is very difficult to apply electrical methods for detection of defects. Though we can use several optical strain sensors, there have been still expensive and had some problems for long term reliability. In the present study, therefore, a novel optical strain sensor using power loss by macro scale bending was developed, and was investigated in detail. Curved optical fiber was attached to specimens. When the specimen is tnesioned, optical power loss changes due to the change of radius of curved optical fiber. The optimum fiber path configuration (quarter circle) was found by computations. The applicability of the sensor was investigated experimentally under the static and cyclic loading. Since the system is simple, it is very inexpensive and has enough reliability.