Parametrised fuselage modelling to evaluate aircraft crash behaviour in early design stages

Abstract

Trade studies during the preliminary design phase play an important role in the design process of a new aircraft. However, the generation and adaption of appropriate finite element (FE) models still takes a lot of time which in turn may prevent comprehensive trade studies and, therefore, lead to time- and cost-intensive redesign during the detailed design phase. Based on a standardised aircraft description, a fuselage modelling tool was developed to automatically generate global FE models for preliminary sizing purposes using beam elements for the fuselage stiffening structure. To be also used in crash simulations these models can be extended in a way that certain regions - where high plastic deformations or failure is expected - may be modelled much finer by the use of extruded profiles and shell elements. Nevertheless, this fine representation is still based on the same standardised aircraft description. In this paper the crash analysis tool AC-CRASH is presented introducing various modelling options and applications. They range from standard section drops with a pure vertical velocity up to full fuselage models under realistic crash and ditching conditions. As an exemplary application of AC-CRASH a vertical drop of a generic fuselage rear section is evaluated in detail.