Flutter analysis of composite lifting surfaces by the 1D carrera unified formulation and the doublet lattice method

Flutter analyses of composite lifting surfaces are presented in this paper. Results were obtained through an advanced aeroelastic formulation based on higher-order 1D structural models coupled with the doublet lattice method. The g-method was used to compute flutter conditions. The Carrera Unified Formulation (CUF) was exploited to build 1D structural models. Refined theories were obtained by using Taylor-like expansions of the cross-section displacement field. In the CUF framework, the order (N) of the expansion is considered as a free-parameter, this means that N can be considered as an input of the analysis. Convergence studies on N can be straightforwardly conducted in order to establish the proper 1D theory for a given problem. Flutter analyses were conducted on several structural configurations. The effect of the stacking sequence and the effect of the sweep angle were analyzed. Results show the enhanced capabilities of CUF 1D in dealing with the flutter analysis of typical composite lifting surfaces with plate-like accuracy and low computational costs.