Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Nonlinear dynamics of a rotating system considering contact with a Shape Memory Alloy coated stator
Submission Author:
Rodrigo Veronese Moreira , RJ
Co-Authors:
Alberto Paiva, Rodrigo Veronese Moreira
Presenter: Rodrigo Veronese Moreira
doi://10.26678/ABCM.COBEM2017.COB17-0434
Abstract
Rotating machines have been used in large scale since the first industrial revolution; thus, for more than a hundred years, dynamical models have been developed and refined in order to describe such systems behavior. A very common phenomenon in rotating dynamics is the intermittent contact between rotor and bearing, which induces undesirable behaviors that may both compromise endurance and prevent the system from working properly. In the last decades, the development of intelligent materials has brought up new possibilities to avoid such inconvenience, taking advantage of particular properties of this kind of materials, for instance: intrinsic energy dissipation and adaptability. This work presents a rotating system model based upon the Jeffcott rotor with four degrees of freedom, being two of them related to the rotor, while the other two refer to the bearing. The bearing inner surface, which is subjected to contact, is coated with Shape Memory Alloy (SMA), whose behavior is described by a first-order phase transition polynomial constitutive model. The SMA coating together with the intermittent contact enable nonlinear characteristics, which lead to a vast richness of dynamical behavior including chaos. Furthermore, the system dynamical response depends on this SMA coating layer temperature, which affects the material behavior (stiffness) and directly influences the impact forces. This element temperature is subjected to two competing phenomena: heating deriving from friction during impact and cooling as a result of convection caused by the interaction with the surrounding environment.
Keywords
Jeffcott rotor, Shape memory alloys (SMA), Falk Model, nonlinear dynamics, chaos
