Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
PARAMETER IDENTIFICATION BY UPDATING THE FINITE ELEMENT MODEL FOR A FLEXIBLE WING
Submission Author:
Thiago Rosado de Paula , MG , Brazil
Co-Authors:
Thiago Rosado de Paula, Vítor Fernandes, Luiz Carlos Góes, David Fernando Castillo Zuñiga, Alain Souza, ROBERTO GIL ANNES DA SILVA
Presenter: Thiago Rosado de Paula
doi://10.26678/ABCM.COBEM2021.COB2021-2033
Abstract
Modeling the aeroelastic behavior of flexible aircraft requires the development of a structural model coupled with an aerodynamic model. The precise forecasting of the flutter is highly dependent on the accuracy of aerodynamic and structural models. For the parametric identification of dynamic structures, the experimental modal analysis should be considered as a special area of the identification system for determining the data of the modal analysis. There are several approaches for updating models to later model the aeroelastic behavior, and in this work, to assess the forms of the modes and to help identify the parameters, a metric called Modal Assurance Criterion (MAC) was used. This metric is a standard in the literature and measures the correlation between two different sources of modal data for the same case. The objective of this work was to update the finite element model for the flexible wing. The first bending modes from the ground vibration test (GVT) were used as a comparison for the MAC. In addition, the flexible wing of the Aeronautics Institute of Technology (ITA) was used. For the simulations, the structural model of a beam was used to represent the structural model of the wing in the Finite Element Method. Also, the MSC Nastran software was used to optimize the flexible wing model in order to identify Young’s modulus, shear modulus, Poisson’s ratio and density. With the optimization, it was verified that the natural frequencies for the first bending modes of the model in finite elements approached the frequencies obtained from the GVT and the values obtained from the main diagonal of the MAC approached the unit value, while outside that diagonal the values approached zero. It was concluded, by obtaining values of the main diagonal of the MAC close to the unit, that it was possible to identify the Young and shear modulus, the Poisson’s ratio and the density for the flexible wing.
Keywords
MAC, GVT, structural model, natural frequencies, aeroelastic systems
