Theoretical study on cross sensitivity of fiber Bragg grating sensor affected by double and triple external variables

In this work, the theoretical model of FBG when it is affected by double external variables （temperature and transverse pressure） and triple external variables （temperature, axial strain and transverse pressure） is deduced, respectively. The simulated results show that the properties of cross sensitivity would change in a certain regulation with the external effects and fiber parameters. At the same time, some valuable suggestions about how to improve the measurement accuracy are put forward as well.