Studies on Sheet‐Metal Compounds with Piezoceramic Modules for Icing Detection and De‐Icing

The authors aim at laying the foundations for the use of sheet‐metal compounds with integrated piezoceramic modules in airplanes or wind turbines. The utilization of piezoceramic modules in aerofoils and rotor blades enables material integrated icing detection or de‐icing. An innovative production technology allows for the integration of piezoceramic modules in sheet‐metal parts. The modules are placed inside an aluminum sheet sandwich structure surrounded by an adhesive layer. A beam for bending with a local sandwich build‐up and an integrated piezomodule is manufactured. The measurement of impedance and phase is used for identification of resonance frequencies. Resonance frequencies change when icing occurs because of its additional mass. First tests on the bending beam identified frequency ranges favorable for icing detection and vibration assisted de‐icing. For this purpose, icing is performed inside a cooling chamber at −25 °C. Furthermore, a demonstrative aerofoil structure (DAS), based on a previously used demonstrator for health‐monitoring, is redesigned and built. Several piezomodules are integrated on positions identified as suitable by a finite element (FE) analysis. The structure with integrated piezomodules is also tested inside the cooling chamber. Icing is detected at the bending beam and the DAS. De‐Icing is possible by means of integrated piezomodules in the bending beam. The obtained results provide information to develop strategies for the use of integrated piezomodules in icing detection and de‐icing systems. The utilization of piezoceramic modules integrated into sheet‐metal compounds of aerofoils and rotor blades offer novel opportunities such as material integrated icing detection or de‐icing. Investigations on a bending beam and on an aerofoil model segment are described. Results of these investigations show that icing can be detected. Also de‐icing is possible by means of the integrated piezomodules.