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This paper presents a study on aeroelastic analyses of composite laminated wings subject to large displacements through the coupling of a nonlinear corotational shell finite element (FE) with an unsteady vortex-lattice method (UVLM) formulation. A FE implemented for the analysis of flat plates has been extended to model laminated composites with different lamina orientations. An UVLM formulation that is capable of coupling with this large displacement structural model is implemented. An explicit partitioned method is evaluated for the coupling of both models, using spline functions to interpolate information from the structural operator to the aerodynamic one, inside a Generalized-α time-marching solution. The resulting aeroelastic formulation provides a framework for the nonlinear aeroelastic analyses of structures made of composite material allowing the characterization of their nonlinear behavior and simulation of the limit-cycle oscillation response. Flat plate laminated wings designed for high flexibility and low flutter speed onset are used as investigation models. Effects of nonlinearities are easily observed in the numerical results, which are promising for expansion of the work and application to the analysis of more refined and complex composite flexible wings.posite beam 11 . For the structural modeling, the capability to model composite shells is part of the desired design goals. The use of finite difference approach for shell modeling 13 does not allow a direct modeling of local characteristics of a composite-made wing. The use of a corotational methodology 7,14,15 allows the simulation of composite plates wings, where aspect ratio considerations used for formulation of beam elements are not valid.In 16 a flat plate model was tested in a subsonic wind-tunnel. The experimental setup aimed identifying aeroelastic characteristics of the model and, in particular, the flutter onset. It showed a good correlation between the experimentally identified and predicted flutter mode shape and onset speed. A large displacement LCO was observed in the post flutter behavior or under certain flow perturbations. Further aeroelastic investigation in the direction of large displacements modeling have been motivated by the observed LCO characteristics. This paper extends the above efforts by addressing laminated composite material and the stability of flat plate wings in forward flight, including stall effects. The "University of Michigan's Nonlinear Membrane Shell Solver" (UM/NLAMS, 14 ) is used in the computational structural dynamics (CSD) analysis side of the aeroelastic problem. This solver has been extended to include laminated composite materials. A UVLM formulation has been implemented and augmented with a stall model. The resulting nonlinear aeroelastic framework has similar complexity and computational costs from both structural and aerodynamics modeling.The goals of this work are: I. Develop an efficient nonlinear aeroelastic framework dedicated to the investigation of orthotropic material influence in the non...

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