(2434)LIFE CYCLE STRAIN MAPPING BY OPTICAL FIBER SENSORS FOR DEFECT AND DAMAGE DETECTION OF CFRP STRUCTURES

摘要

We propose structural health monitoring (SHM) technology based on the strain mapping of composite airframe structures through their life cycles including the stages of molding, machining, assembling, operation, and maintenance. Our SHM system detects damage and deformation harmful to the structures by strain mapping using fiber Bragg grating (FBG) sensors. In this paper, we firstly carried out a strain monitoring test of CFRP mock-up structure through the life cycle including the stage of molding, machining, assembling, and operation. The experimental result confirms that the strain which occurs in each life cycle stage can be measured by FBG sensors embedded in molding stage and demonstrates the feasibility of life cycle structural health monitoring by using FBG sensors. Secondly, we conducted the strain monitoring test of CFRP scarf-repaired specimen subject to fatigue load. FBG sensors were embedded in the specimen and their reflection spectra were measured. Specimens were inspected by pulse thermography. As a result, strain measured by FBG sensors changed sensitively with debonded area of repair patch, which demonstrates that the debondings of repair patches in scarf-repaired composites due to fatigue load can be detected by FBG sensors.