Sensitivity boost of rosette eddy current array sensor for quantitative monitoring crack

In order to boost the sensitivity of the rosette eddy current array sensor, a crack-monitoring system was established, and an equivalent sensor model was developed. The trans-impedance model output signal amplitudes were in good agreement with the validation experimental data. The washer model sensitivity of the integrated sensor was optimized. The results indicate that washer with high relative permeability and low conductivity can effectively boost the sensor's sensitivity. The magnetic membrane washer employed in the experiment boosts the sensitivity of the sensor's 4 channels by 14.7%, 18.9%, 10.7%, and 19.3%, respectively. Thereafter, an experiment that used the integrated sensor with washer monitoring crack propagation under a constant load was performed to validate the model. The experimental results prove that the sensor has the capability for performing quantitative monitoring of crack propagation.