Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Reduced order modeling of highly flexible structures
Submission Author:
Arthur Veronese , SP
Co-Authors:
Arthur Veronese, Flavio Luiz Cardoso-Ribeiro, Fernando José de Oliveira Moreira
Presenter: Arthur Veronese
doi://10.26678/ABCM.COBEM2021.COB2021-0825
Abstract
The search for more fuel-efficient aircraft is an everlasting goal of the aerospace industry. This ambition has led to some aircraft designs with a very high aspect ratio wing. For these cases, the linear theories that use the assumption of small displacements begin to get inaccurate, needing the use of a nonlinear theory to calculate displacements. Commercial software can provide a very accurate calculation of these displacements but can be too computationally expensive to use for a real-time simulation. In this context, this paper brings a lumped mass strain-based nonlinear structural model, and a reduced order model to further decrease the computational time of simulation while generating accurate displacements values. This work also studies the influence of nonlinear terms on the structure dynamic aiming for high calculation performance. If successful, this structural model can also be used as input of more complex problems that include the whole aircraft, such as aeroelasticity and control systems. In the proposed model, the generalized coordinates are the element rotations connected with torsional springs enabling motion of in-plane bending. A modal decomposition and truncation model order reduction is applied to produce a nonlinear reduced order model, where the generalized coordinates are the natural modes of the structure. The number of natural modes required to provide accurate displacement results depends on the complexity of applied external force, where simpler forces such as single concentrated forces require fewer modes and more complex forces such as multiple points and distributed forces require more modes. The reduced-order model was able to reduce up to 68% of computational time for a static deflection and 95% for a time simulation, while reducing the order of the model from n=20 to n=2, and still producing accurate deflections results compared to the literature even for large displacements. This work also concluded that the high order gyroscopic term that consumes most of the computational performance can be neglected, greatly contributing to these results.
Keywords
MOR, structures, non-linear, Aeroelasticity
