Mistuning Modelling and Analysis of Bladed Disc System

Speaker : Rahul Kumar

Venue : Google Meet (meet.google.com/ybt-oyvs-ecv)

Date : 19th March, 2021 (Friday)

Time : 5.00 P.M.

Abstract

Bladed disc system or rotor, which is an integral part of turbines and compressors, exhibits very complex vibrations during operation. Typically, these bladed disc structures are designed to be rotationally periodic i.e. a sector repeats itself comprising of a blade and a part of the hub. However, because of imperfections in manufacturing tolerances, wear and tear during operation the sectors are no longer identical. This results in the loss of periodicity and the system is referred to a mistuned system. The sectors of mistuned system are assumed to have random spatial fluctuations in system parameters. Consequently, it leads to mode localization in the bladed disc system and results in localized stresses leading to failure. A surrogate stochastic reduced order model is developed for the analysis of randomly parametered structural systems with complex geometries. It is assumed that the mathematical model is available in terms of large ordered finite element (FE) matrices. The structure material properties are assumed to have spatial random inhomogeneities and are modelled as non-Gaussian random fields. A polynomial chaos expansion (PCE) based framework is developed for modeling the random fields directly from measurements and for uncertainty quantification of the response.

About the speaker

Rahul is currently a research scholar in the Dept. of Applied Mechanics, Indian Institute of Technology Madras. He jointly works under the supervision of Prof. Shaikh Faruque Ali and Prof. Sayan Gupta. He is currently working on the mistuning analysis of bladed disc system in probabilistic framework. His work includes the development of data driven based stochastic reduced order model to analyse the problem.