Dynamic Stress Analysis of Viscoelastic Rotor

Abstract

The present work deals with the study of stresses in viscoelastic rotor which are dynamic in nature. Due to internal damping of the rotor material, dynamic characteristics get affected and hence it is studied to understand the behavior in terms of Campbell plot, mode shapes etc. This study starts with modelling of beam, where viscoelastic material was considered. The solution for time domain was obtained through state space approach. For discretizing the continuum finite element method is used based on Euler Bernoulli beam theory. Then stresses were found for cantilever beam. This modelling was further used to model viscoelastic rotor. Stable limit speed as a function for different torque is plotted, which is found to remain constant for varying torques. The bending as well as shear stresses were calculated. For designing of rotor here non-ferrous material was considered as they do not exhibit endurance limit. Then the rotor was analyzed based on dynamic shear and dynamic bending stress, equivalent stresses were obtained and the location which was subjected to maximum stresses was focused and using design equations, life of rotor before failure was found.