Modified cantilever beam shaped FBG based accelerometer with self temperature compensation

This paper focuses on Fiber Bragg Grating (FBG) based accelerometer design. The accelerometer structure consists of inertial mass supported by an L-shaped modified cantilever beam having non-uniform cross section area connected to base by a thin neck element which acts as strain concentrated centre hence an optimum zone for FBG sensors placement. It has a working bandwidth below the structure's natural frequency and responds linearly to vibrations. The parameters for the structure design have been optimised on SolidWorks 2012 platform. Experimental trials yield sensitivity of 46 pm/g for frequency below 50 Hz and 306 pm/g for frequency above 150 Hz. A mathematical model for the accelerometer structure's natural frequency modes is also presented with detailed analysis for different combinations of inertial mass-frame assembly.