Multi-Modal Dynamic Vibration Absorber Design for Aerodynamic Surfaces Using Optimization

Resumo

Dynamic Vibration Absorbers (DVAs) are devices that aim to reduce the vibration amplitudes of systems
subjected to external forces. When a DVA is coupled to a primary system, it promotes the reduction of vibration at
a certain frequency of operation. The aerodynamic surfaces of aircraft, such as wings, are subject to problems, for

example, those caused by the Flutter effect, dangerous phenomenon found in flexible structures subject to aerody-
namic forces such as aircraft, buildings, bridges, among others. This phenomenon is characterized by the coupling

of two oscillations, flexion and torsion, which occurs due to the interactions between aerodynamics, low stiffness
and inertial forces in a structure. In order to simultaneously mitigate the amplitudes of vibration in the vicinity
of both oscillations in the wing, this work proposes the design and optimization of a passive MultiModal DVA
(MMDVA) whose main feature is the ability of reducing vibration at the vicinity of various resonance frequencies
of a primary structure. This justifies why it is used in the current application. However, it is not easy to determine
the optimum constructive parameters of these MMDVAs and therefore it is necessary to use optimization methods
to guarantee that they are tuned to the wing frequencies (flexional and torsional). The global optimization heuristic
Genetic Algorithms (GAs) was used for this purpose and demonstrated to be efficient.