Vertical impact simulations of a full-size and simplified scaled models of an aircraft fuselage section

Abstract

Computer modeling and simulations on the crashworthiness of aircraft using validated models have provided insight into the energy-absorption characteristics of structures and have allowed parametric studies in the evaluation of different crash energy management designs. In this study, the dynamic responses of a detailed and simplified full-size, and scaled fuselage models in vertical impact are investigated. The detailed full-size model, constructed from a Boeing 737 mid fuselage section, consists of a stiff auxiliary fuel tank and a cargo door. The detailed full-size model is dropped from a height of 4.26 m (14 ft) onto a rigid surface, which corresponds to a vertical impact speed of 9.14 m/s (30 ft/s). The drop simulations are performed using the non-linear explicit code, LS-DYNA. Correlation of the detailed full-size model with the physical test conducted by the Federal Aviation Administration is demonstrated. Scale modeling technique applied to the aircraft fuselage section is utilized and for scaling purposes, a simplified full-size model is constructed without the auxiliary fuel tank and cargo door. The crash responses of the simplified full-size models in relation to the detailed full-size model are shown and discussed. The scaling approach involves geometrical scaling of the simplified full-size model with scale factors of 1/5th, 1/10th and 1/20th. The vertical impact simulations of the scaled models are carried with identical impact speed as that of the detailed full-size model. General scaling laws for geometry, mass, velocity, acceleration and forces are utilized to predict the results for the scaled models. The approach and results presented in this study have demonstrated an efficient and innovative method on the design and crashworthiness of a fuselage section.