A Novel Nonlinear Aerodynamic Model of Flutter and Buffeting Based on Condensed DOFs Technology

Abstract

This paper proposes a novel Inertial Coordinates Independent (ICI) aerodynamic model using the condensed degrees of freedom (DOFs) technology. Through a management of the ICI inputs, the aerodynamic forces will not be restricted by the selection of inertial coordinates and will have the same prediction effect for different coordinates. In addition, by including the self-excited force and the buffeting force, and by reducing the appropriate number of aerodynamic DOF, the ability of the proposed model to describe the nonlinear aerodynamic characteristics such as memory effect is enhanced. It can be directly applied to any non-stationary inputs in the time domain, and improve its applicability to structures with large deformations. With the self-developed computational fluid dynamics (CFD) software, the aerodynamic to-be-identified parameters can be identified by a data-driven method, and the correctness of each term of this model has been verified. Finally, the overall accuracy of the proposed method is examined by comparing both the self-excited force and the hysteresis patterns of ICI model with those results based on a series of CFD simulations of a streamlined bridge deck section.