Primary structure mass estimation in early phases of aircraft development using the finite element method

Kurzfassung

Accurate estimations of the primary structure mass are crucial to aircraft pre-design activities. This paper presents a method that uses parametric-associative geometry and finite element models created in the software environment Catia-V5 for estimation of the primary structure mass. A major requirement for the developed tool is its suitability for use in different phases during the aircraft pre-design process. In very early phases mass estimations for different aircraft configurations need to be performed. In later phases different structural concepts have to be assessed and compared. A novel approach is presented that combines the idealization of shells by ABDstiffness matrices with very adaptable parametric-associative models that provide zones to which different design concepts may be assigned. In order to support different project phases during the early aircraft development different sizing algorithms are integrated in the tool. For a vertical tail plane two studies are conducted to prove the tool’s suitability in realistic use case scenarios. The first study represents a typical use case at an early project stage during the aircraft pre-design. In this study different planform configurations are analyzed and mass sensitivities with respect to sweep, taper ratio and aspect ratio are studied. The second study represents a use case typical of a later project phase. In this study mass sensitivities are computed for designs with different spar positions and variations in stringer pitch also taking into account manufacturing constraints. The two studies can be successfully conducted proving the tool’s suitability for mass estimation in different phases of pre-design.