繰返し荷重を受ける場合のFBGセンサを用いたひずみ計測時自己温度補償方法

抄録

A self-temperature compensating strain-measurement technique is proposed using a single fiber Bragg grating (FBG) sensor for a cyclic loaded testing-object heated moderately by itself. The technique adopts a moving-averaging method using the forward and backward Bragg wavelength data from an FBG sensor. One case was considered: a sinusoidal strain-change and a linear-functional temperature-change are assumed. In the case, it was derived that the self-temperature compensating strain-measurement is possible. The technique was applied to a test result, which is a strain-measurement result of a rotating aluminum-beam using an FBG sensor. The attempt was significantly successful. The self-compensated maximum and minimum strains were kept almost same values for about 1 hour, although the non-compensated strain s shifted to the tensile strain side as testing-time. These results indicate that FBG sensors are appropriate for applying to measuring dynamic phenomena than for applying to measuring quasi-static phenomena. The self-temperature compensating technique will be applicable to fatigue testing of metal materials, strain-measurements in vibration-tests, and strain measurements of rotating mechanical elements in machineries.