Sensitivity-Enhanced Fiber-Optic Diaphragm Accelerometer Array by Optimizing Multiturn Fiber Coils

This study proposes an innovative approach for sensitivity enhancement in fiber-optic diaphragm accelerometers (FODAs) via geometrically optimized multiturn fiber coils (MTFCs). Finite element analysis (FEA) was employed to systematically analyze strain distribution characteristics in MTFC. Experimental validation demonstrates that, preserving the original FODA mechanical structure, and varying the turns and layers of the MTFC, induces measurable sensitivity variations without resonant frequency variation. A comprehensive performance evaluation of MTFC with distinct cladding/coating diameters and sensing fiber lengths was conducted through rigorous testing, ultimately demonstrating a sensitivity of 36.52 rad/g accompanied by a resonant frequency of 2400 Hz and a flat response (2.15 dB) across 10 Hz–1 kHz. Capitalizing on this optimization framework, a multiplexed sensing array incorporating weak fiber Bragg grating (wFBG) element was successfully implemented, demonstrating operational viability for real-time distributed acceleration monitoring across extended multipoint measurement networks.