Study on a fiber Bragg grating accelerometer based on push-pull compliant cylinders

A compact double fiber Bragg gratings(FBGs) accelerometer based on push-pull compliant cylinders is proposed. The mechanical model is demonstrated. The accelerometer contains four parts, double cylinders, double FBGs, inertial mass, shell. Double cylinders and mass block which can reduce the cross-sensitivity and protect the FBGs from being damaged. The material of the cylinders is two-component vulcanized silicone rubber. The amplitude-frequency and sensitivity of the accelerometer are theoretically analyzed and experimental measured. Experimental results show that the resonant frequency of the accelerometer is 640Hz, the sensor has a broad flat frequency range from 20 to 500Hz, the sensitivity of the accelerometer is about 48.5pm/G with a linearity of 0.999, while the two FBGs is contributed to the sensitivity enhancement, temperature and transverse sensitivity independent. The accelerometer has a wide frequency and high sensitivity, making it a good candidate for the cross-well micro-seismic monitoring.