An Improved Beam Formulation for Aeroelastic Applications

A refined beam model for the linear static aeroelastic analysis of generally oriented lifting systems is described in this paper. It is aimed at beam-like structures such as classical and unconventional wing configurations. The structural formulation of refined beam finite elements is embedded in the framework of Carrera Unified Formulation. Increasing accuracy in predicting effects of warping, in-plane deformation is obtained by considering as a free parameter the order of the displacement field expansion over the cross-section. Linear steady aerodynamic loads are described via the Vortex Lattice Method and the transfer to their energetically equivalent structural loads is performed by the Principle of Virtual Displacements. Thanks to the accuracy of refined elements, the coupling of structural and aerodynamic fields is performed via the Infinite Plate Spline method. The procedure involves a set of pseudo-structural points placed on the reference surface of the wing system. Different beam elements as well as different higher-order models are considered for the analysis of various cross-section geometries and loading cases. The structural results are validated with benchmarks retrieved from the classical models and NASTRAN. Aeroelastic results show well agreement with NASTRAN solution for a number of wing configurations. The proposed higher-order model proves its increasing accuracy in predicting aeroelastic responses with respect to analyses based on classical beam theories.

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