Análises de incertezas e sensibilidade intervalares aplicadas em uma máquina rotativa com eixo de material compósito

Abstract

Composite materials present currently several applications in different types of components and structures. This is due to their wide range of advantages, such as high stiffness and resistance as compared to their weight and ability to change stiffness and damping capacity through the manipulation of their properties. In this way, researchers in the field of rotordynamics have seen the use of these materials instead of metallic shafts as an opportunity to maximize operating speeds, to reduce the time of acceleration and deceleration, to increase structural efficiency, among other aspects. Therefore, in the present contribution, a finite element model of the rotating composite shaft was initially formulated by considering the Kelvin-Voigt rheological model, from which the matrices D𝑖 and K𝑖 were obtained. The disc, bearings, and mass unbalance were also taken into account in this model. The SHBT homogenization method, which defines the properties of the composite shaft, was also presented. Then, uncertainty and sensitivity analyses devoted to the composite shaft parameters were applied. The obtained results demonstrated the parameters that influence most the vibration responses of the shaft according to the frequency and rotation speed. The Campbell diagram indicating the critical and instability speeds of the rotor was also presented.