Surface Ice Detection and Accretion Monitoring on Composite Structures employing Electromechanical Impedance Method

Detection of surface ice is of utmost importance in many industrial applications because it can induce performance degradation and be even life threatening. This paper deals with the identification of ice accretion using permanently installed sensors on top of glass fiber composite typically adopted for wind turbine blades. The electromechanical impedance (EMI) of the distributed transducer networks is monitored accounting a wide frequency spectrum (up to 400 kHz) as well high excitation amplitudes (up to +/-100 V). The analysis of ice accretion is performed by employing several metrics, such as the root mean square deviation (RMSD) and the mean absolute percentage deviation (MAPD). Moreover, the principal components analysis (PCA) is introduced to analyze the EMI spectra in a dimensionality reduced 2D feature space. It is demonstrated that the EMI method has the ability to qualitatively assess ice accretion on a composite panel.