Abstract: This article investigates the effect of oblique struts on the crashworthiness of fuselage sections for a class of typical civil aircraft fuselage sections with oblique struts under the cabin floor. A finite element model of the cabin floor and its underneath structure is developed. Rigid blocks are used to simulate the structure above the cabin floor and the mass of the passenger and the seat. The impact characteristics of fuselage sections subjected to 7 m/s vertical velocity are analyzed. Several typical conditions of oblique struts are considered, i.e. strut of different cross-sections with and without holes, rigid struts and no struts. A contrastive analysis is given of acceleration histories, failure mode and energy absorption of different fuselage sections. The result shows that there is a certain stiffness of the strut for the fuselage section that will exhibit good performance on crashworthiness. But more than two high accelerations may appear if the stiffness of the strut is increased or decreased.

Key words: crashworthiness, fuselage, finite element method, struts, acceleration, energy absorption, failure mode