Real-time monitoring of deformation of large structure parts is of great significance and the deformation
of such structure parts is often accompanied with the change of curvature. The curvature can be obtained
by measuring changes of strain, surface curve and modal displacement of the structure. However, many
factors are faced with difficulty in measurement and low sensitivity at a small deformation level. In order
to measure curvature in an effective way, a novel fibre Bragg grating (FBG) curvature sensor is proposed,
which aims at removing the deficiencies of traditional methods in low precision and narrow adjusting. The
sensor combines two FBGs with a specific structure of stainless steel elastomer. The elastomer can transfer
the strain of the structure part to the FBG and then the FBG measures the strain to obtain the curvature.
The performed simulation and experiment show that the sensor can effectively amplify the strain to the
FBG through the unique structure of the elastomer, and the accuracy of the sensor used in the experiment is
increased by 14% compared with that of the FBG used for direct measurement.