Eventos Anais de eventos
MECSOL 2022
8th International Symposium on Solid Mechanics
Localization of vibration modes in aeronautical turbine blades
Submission Author:
Elizabete Silva , SP , Brazil
Co-Authors:
Elizabete Silva, Reyolando Brasil
Presenter: Reyolando Brasil
doi://10.26678/ABCM.MECSOL2022.MSL22-0129
Abstract
In this work, the phenomenon of localization of vibration modes in quasi-periodic structures with linear behavior is studied. In particular, it is applied in the field of Aeronautical Engineering, in aeronautical gas turbine blades, which have periodic characteristics, weakly coupled to each other through the rotor disk, taking into account possible small imperfections. Linear systems, faced with the disorder caused by small imperfections can lead to the confinement of vibrational energy in certain regions of the structure, a phenomenon known as Mode Location. This phenomenon can cause catastrophic failure due to high vibration amplitude and fatigue. The identification and study of the location effect from a modal perspective, as well as the response of the structure and its components to dynamic load, is of fundamental importance, as it is a diagnostic tool for possible preventive mitigation actions or even use of this phenomenon in damping of the system. Through the implementation of computer simulation via Matlab and Ansys software, based on the Finite Element Method, the distribution, interference, and consequence of vibrational energy on the adopted model is verified based on periodic and ordered dynamic characteristics or aperiodic and disordered. The real case considers small variations of the characteristics (length, rigidity, angulation), resulting from manufacturing tolerances or FOD (Foreign Object Debris) impact. The proposed implementation graphically displays the normalized vibrational energy amplitude as a consequence of the emergence of the phenomenon of localization of vibration modes in substructures that may be restricted to one or a few blades of the structure.
Keywords
vibration modes, Vibrational energy, Finite Element Method, Turbine Blades, Location of modes
