Eventos Anais de eventos
DINAME 2017
XVII International Symposium on Dynamic Problems of Mechanics
Optimum design of a set of dynamic neutralizers to passive vibration control considering physical parameters, location and viscoelastic material variables
Submission Author:
Francielly Silva , PR , Brazil
Co-Authors:
Francielly Silva, Carlos Alberto Bavastri
Presenter: Carlos Alberto Bavastri
doi://10.26678/ABCM.DINAME2017.DIN17-0140
Abstract
Structures exposed to high level of vibration due to resonance phenomena or dynamic instability can fail or have, in general, your life time reduced. In some cases, the unwanted noises level affect its operation for which the equipment or structure were designed. In these cases, a feasible solution to reduce vibration levels and/or irradiated noise is the use of viscoelastic dynamic neutralizers (VDNs). These devices are used with success in vibration control, due to elevate capability of the viscoelastic material to dissipate a large vibration energy. The vibration and sound group (GVIBS) has a methodology that consider the natural frequency and the optimal position of one-degree-of-freedom VDNs, to reduce vibration levels of a linear dynamic structures, known as primary system, in a broadband of frequency. In this context, the present study aims to develop a methodology for optimal design of VDNs considering, also, in the design variable, the viscoelastic material between a set of characterized materials. The optimal configuration is obtained by the application of a hybrid optimization technique which uses Genetic Algorithms (considering continuous and discrete variables in the same design vector) in order to approximate the global minimum and, after that, a nonlinear programming method to perform a local search. To evaluate the proposed methodology, simulations were performed on a metallic plate where one or more neutralizers are considered. A new proposal to calculate the VDNs mass, allows obtaining different values for different VDNs to control one or more modes, which makes the vibration attenuation be more efficient. The results for the optimal design of VDNs, for a given temperature, show promise and the inclusion of the viscoelastic material in the optimization process, proves to be an interesting aspect in the vibration control, once we can use a better material in different situations (environment temperature, band of frequency, primary system, between others).
Keywords
Passive Vibration Control, Dynamic neutralizers, Viscoelastic material, Optimization
