COMPUTATION OF NATURAL FREQUENCIES AND MODE SHAPES OF A PERIODIC STRUCTURE VIA PERTURBATION ANALYSIS AND POLYNOMIAL CHAOS

Open Access
Author:
Bares, Jonathan
Graduate Program:
Mechanical Engineering
Degree:
Master of Engineering
Document Type:
Master Thesis
Date of Defense:
December 17, 2009
Committee Members:
  • Alok Sinha, Thesis Advisor
Keywords:
  • COMPUTATION NATURAL FREQUENCIES MODE SHAPES
Abstract:
The goal of this paper is to analyze the modal characteristics of a mistuned bladed disk assembly. We compute the expected value and standard deviation of eigenvalues and eigenvectors of such a system by using a polynomial chaos technique. The model of the bladed disk assembly considers only one mode of vibration of each blade and the mistuning phenomenon has been simulated by treating the modal stiffness of each blade as a stochastic variable. A Monte Carlo simulation and a Taylor series expansion are used to validate the result of this method.