Advanced models for static and dynamic analysis of wing and fuselage structures

Recently, an hierarchical formulation based on the Carrera Unified Formulation (CUF) was introduced by adopting polynomial expansions of the displacement field above the cross-section of the structure. The finite element method was exploited to develop numeri- cal applications by employing the principle of virtual displacements. In the CUF framework the finite element matrices and vectors are expressed in terms of fundamental nuclei whose forms do not formally depend on the order and the class of the model. Two classes of 1D higher-order models have been developed according to the CUF. The Lagrange Expansion (LE) models were built by means of four- (L4) and nine-point (L9) Lagrange-type polyno- mials. The Taylor Expansion (TE) models exploit N-order Taylor-like polynomials. The classical 1D models are obtained as special cases of TE. This paper proposes advanced 1D theories for static and dynamic analysis of aeronautical structures. A number of typical stiffened-shell structures were analyzed. Classical 1D (Euler-Bernoulli and Timoshenko) and refined models were implemented by exploiting the 1D CUF. Finite element models made with a commercial software were used for comparison purposes. Results have high- lighted the enhanced capabilities of the present formulation which is able to detect solid and shell-like accuracies with significantly lower computational costs.