A reduced-order nonlinear aeroelastic framework for wings undergoing large deflections

Modern aircraft designs aim to enhance overall performance and reduce fuel consumption, thereby minimising costs. The growing interest in high-aspect-ratio wings stems from the potential gains in aerodynamic performance. Concurrently, the utilisation of composite materials in the aircraft primary structure for weight reduction is increasing. Both aspects influence wing flexibility and may result in larger wing deflections than those of existing aircraft during operational conditions. Under appropriate loading conditions, the wing deflections can be large enough to surpass the threshold of geometrically linear analyses. This adds complexity to both structural and aeroelastic analyses.

The primary challenge in nonlinear structural analyses arises due to the replacement of the scalable linear methods with the iterative predictor-corrector methods. This can significantly exacerbate the required computational effort. The same limitation also extends to aeroelastic analyses. Beyond the computational aspects, the larger wing deflections introduce aeroelastic effects that cannot be modelled using the linear methods. Prior studies have demonstrated the influence of geometric nonlinearities on aeroelastic characteristics. Notably, a majority of numerical models used to investigate these effects so far rely on variants of geometrically exact beam theory for incorporating nonlinear structural kinematics. While this approach makes the analyses computationally efficient, it involves transforming finite element models into equivalent beam models.....