Model-based structural integrity assessment of helicopter fuselage during harsh landing

Nowadays the assessment of a harsh landing condition for helicopters is based on the pilot's judgment. This can lead to a misclassification of the landing condition, thus affecting the system safety or requiring unnecessary maintenance. The availability of a tool for the automatic assessment of the harshness of the landing condition will improve the efficiency of the current helicopter operations. This paper describes a preliminary step for the validation of a coupled multibody - finite element modelling environment, useful to estimate the most critical zones within the fuselage as well as the occurrence of plastic damage. Experimental harsh landing tests have been carried out on a retired Mil Mi-8 helicopter and 3D-scan measures of the helicopter geometry have been taken during helicopter tests. Repeated drops from increasing altitude have been performed, each time recording the 3D surface geometry at some critical locations, thus allowing the validation of the numerical model.