A method to utilize string-strain-change induced by a transverse force and its application in fiber Bragg grating accelerometers

摘要

#$%^&*AU2012101789A420130110.pdf#####Abstract When a transverse force is applied to a stretched string that is fixed by its two ends, the string bends and the strain of the string increases to balance the transverse force. As a result, the axial force along the string can increase much more than the transverse force applied. By developing Fiber Bragg Grating (FBG) accelerometer based on transverse force rather than axial force, the force required for maintaining a high sensitivity is much smaller and thus the size of FBG accelerometers can be dramatically reduced. More importantly, FBG accelerometers based on transverse force have an inherent low cross-axial sensitivity. Simultaneous measurement of acceleration, temperature and displacement is realized by using two under-tensioned FBG. Displacement change is calculated by using the differential of the two FBG results. Meanwhile temperature and acceleration is calculated by using the arithmetic mean of two FBG results, while temperature and acceleration are distinguished by applying lowfrequency-pass and high-frequency-pass filter respectively to the arithmetic mean.3a L x 2Fj +AFI 2 1F, +AF, C' F, Fig. 1 a b 3b Fig. 2