A hybrid FBG-based load and vibration transducer with a 3D fused deposition modelling approach

A fibre Bragg grating (FBG)-based load and vibration transducer (FLVT) was developed using a 3D fused deposition modelling (FDM) approach. A newly FLVT was designed by the equal-strength cantilever beam in which the FBG sensors were embedded in the beam during the FDM process. The temperature effect was eliminated by the temperature sensor in the vibration sensing unit. The parameters of the proposed FLVT was examined by the finite element method. The simulated results were matched well with the theoretical analysis results and laboratory calibration results. The proposed transducer has the pressure measurement sensitivity of 0.01274 nm kPa−1 for the earth pressure below 150 kPa. In addition, the proposed transducer could accurately measure low-frequency vibration signals with maximum frequency of 4 Hz and the maximum displacement amplitude of 4 mm with sensitivity of 117.6 pm g−1. The measurement accuracy and stability were carried out. Results shown that the maximum relative errors between the calculation results and the experimental results was 1.3%. The effect of vibration direction was also analysed for the proposed FLVT. The results indicated that the transversal vibration has less influence on the longitudinal vibration. The outcome of this study indicated that the proposed FLVT provide a newly approach for the measurement of earth pressure and soil vibration in one transducer which is quit suit for soil mass.