Abstract
When strain is measured with the center wavelength of an FBG sensor, the accuracy can be decreased by large temperature change. In this research, a device using single FBG sensor was studied to measure both strain and temperature simultaneously. The device named "Laminate Patch" is a laminate of 90° plies of CFRP and an epoxy plate including an FBG sensor. When temperature decreases, the cross section of the optical fiber is deformed because of the thermal residual stress. The deformation causes the birefringence and widens the reflection spectrum. It is expected that, therefore, the spectrum width has specific relation to the temperature change. Experimental results showed that the FWQM changed in proportion to the temperature change and the strain. Therefore, it was revealed that strain and temperature can be calculated from the center wavelength and the FWQM.
