Study of Medium Velocity Impacts on the Lower Surface of Helicopter Blades

This work focuses on the study of oblique medium velocity impacts (∼70m/s) on the lower surface of helicopter blades. The blade is assimilated to a composite sandwich panel with a thin woven composite skin stabilized with a foam core. A numerical study is performed through the use of a specific Finite Element formulation developed to model the behavior of the woven composite skin during an impact. Numerical and experimental results are compared. The proposed modelling strategy well correlates the tests. The modelling is then used to study the influence of the curvature of the blade and of the centrifugal load on the impact response.