Mechanics of Nano, Micro and Macro Composite Structures Politecnico di Torino, 18-20 June 2012 A. J. M. Ferreira, E. Carrera (Editors) http://paginas.fe.up.pt/~icnmmcs/ EFFECT OF WARPING DUE TO AERODYNAMIC LOADINGS IN COMPOSITE WINGS Erasmo Carrera, Alberto Varello, and Alessandro Lamberti Politecnico di Torino Department of Aeronautics and Space Engineering Corso Duca degli Abruzzi, 24 10129, Torino, Italy e-mail: alberto.varello@polito.it, web page: http://www.mul2.com Key words: 1D Refined Models, Vortex Lattice Method, Unified Formulation, Composites. ABSTRACT With the advent of composites, the accurate evaluation of the response of deformable lifting bodies when subjected to steady and unsteady aerodynamic loadings becomes an even more challenging issue for the aeroelastic design of aerospace vehicles. Static response analyses of composite wings subjected to aerodynamic loadings are presented in this paper. Wing structures are modeled via refined finite elements in the framework of the 1D Carrera Unified Formulation (CUF). CUF 1D models have recently been developed for isotropic [1, 2] and composite structures [3]. CUF models exploit arbitrary order expansions of the generalized variables above the cross-section of the structure. In this paper, Taylor-like polynomial expansions are adopted and the order N of the expansion is a free-parameter of the formulation. In other words, any-order models can be obtained with no need of ad hoc formulations by exploiting a systematic procedure to build finite element matrices in a form which is independent of the accuracy of the model. 1D CUF models allow to detect highly accurate shell-like static deformations and modal shapes of thin-walled structures with a significant reduction of computational costs. 1D CUF structural models were coupled to the Vortex Lattice Method, VLM, in [4]. The formulation was extended to the static aeroelastic analysis of lifting surfaces made by metallic and composite materials [5]. The computation of linear steady aerodynamic loads refers to the Vortex Lattice Method presented by Katz and Plotkin [6]. As usually adopted in preliminary aeroelastic design, the aerodynamic computation by the VLM did not consider the airfoil- shaped section. Hence, an analysis tool for airfoils, wings and planes operating at low Reynolds Numbers, XFLR5, is herein adopted in order to accurately describe the aerodynamic field over the wing affected by the airfoil pressure distribution. In this paper, non-classical effects such as airfoil in-plane deformation and warping are introduced by enriching the displacement field over the cross-section of the wing. A number