Dynamic behaviour of precracked bimaterial structures applicable to wind propellers
Final Report Abstract
A mathematical model as an approximation of the pre-cracked rectangular part of the blade of a wind turbine under time harmonic load is developed and applied. The model consists in a pre-cracked bi-material structure where the interface between the structure plates can debond according to the assumed elastic-brittle behavior, followed by a cohesive one. Two different material structures regularly used to build the wind blades (the epoxy-glass and epoxy-carbon composites) are studied and the influence of the amplitudes and frequencies of the external time harmonic load on the elastic and cohesive debond lengths are commented. The cases of a full degradation of the structures along the interface as well as the safety zones for frequencies are commented.
