Investigation on guided waves propagation across ice layers

Icing conditions are threatening for a variety of engineering applications. When accreting on the aircraft surface, ice may lead to catastrophic accidents while its deposition on turbine blades can overload the components reducing power and inducing damage. The first way to protect engineering constructions from icing issues deals with early detection of ice. Ultrasound has been demonstrated to be effective for detecting changes of the structure which it is propagating through. Guided waves interact with emerging flaw and discontinuity, including ice accreting on the surface. This paper introduces an experimental campaign carried out on composite structures subject to icing. The building up of planar ice onto surface structure is analysed. Furthermore, a parametric investigation is carried out by finite element modelling to look into the interaction between wave and ice while varying its dimension. Experimental findings demonstrate the ability of guided waves to detect ice layers accreting onto surface. In addition, the ice is likely to be identified from the scattering of guided waves resulting in different transmission and reflection characteristics. Instead, numerical outcomes show how the interaction of guided waves depends upon the thickness and length of the ice.