Electromechanical admittance method to monitor ice accretion on a composite plate

Reliable ice detection is crucial in many industrial applications, such as airplanes or wind turbines. The presence of ice can lead, on one side, to performance degradation, such as higher fuel consumption or less electrical energy production, and, on the other, to enhanced structural loads, representing a threat for both the affected structures and surrounding people as well. In order to control icing phenomenon, a set of distributed sensors, able to detect the surface contaminant and automatically triggers deicing actions, may represent an effective solution. In this paper, the performances of a surface ice detection system, based on the electromechanical admittance technique and multiple piezoelectric transducers, are analyzed considering, as target structure, a composite plate. The investigation accounts a wide ultrasonic frequency spectrum and some metrics are calculated to define effective detection indices. In addition, the principal components analysis technique is adopted to process the spectra of admittance. The obtained results prove that the proposed method allows to evaluate the accretion of ice on a composite laminated structure qualitatively.