Session: 28-06 System Dynamics & Identification Methods

Paper Number: 104069

104069 - Sensitivity Analysis of Transient Forced Response of Mistuned Bladed Disks Under Complex Excitation and Varying Rotation Speed 

During fast accelerations and decelerations of gas-turbine engines, the transient vibration effects in bladed disk vibration become significant and the transient response needs to be efficiently and accurately assessed.   

In this paper, an effective method is developed for efficient calculations of the sensitivity of the transient vibration response for mistuned bladed disks under varying rotation speeds. The sensitivities are calculated with respect to two major factors: (i) the blade mistuning and (ii) the rotor acceleration/deceleration rates. The method uses the large-scale finite element modelling of the bladed disks allowing the accurate description of the dynamic properties of the mistuned bladed disks. The method can be applied for a case when the loading is the transient load, with the amplitude and frequency spectrum changing with rotation speed. The dependency of the modal characteristics on the rotation speed is included in the formulation of the sensitivity analysis method. Effective reduced order models are used to reduce the computational cost, which can adapt to the effects of the varying rotation speed on the natural frequencies and mode shapes of mistuned bladed disks under transient conditions. The expressions for the sensitivities are derived analytically which provides high accuracy and speed of the calculations.

The method has been implemented in a computer code and thoroughly verified using a set of test cases. The studies of the sensitivity of transient forced response studies have been performed on realistic bladed disk models.

Presenting Author: Evgeny Petrov University of Sussex

Presenting Author Biography: Ph.D in Mechanical Engineering from Kharkov Polytechnic University, Ukraine, and then several positions from Junior to Principal Researcher at this university. In 1996-1997 – Research Fellow at the University of Liege, Belgium. From 1998 to 2012 is Senior Research Fellow at Imperial College, London. From the end of 2011 till now Reader in Structural Dynamics at Sussex University. My area of expertise is the analysis and optimization of nonlinear structural dynamics for gas-turbine engine and turbomachinery structures.

Authors:

Tong Jing Nanjing University of Aeronautics and Astronautics
Chaoping Zang Nanjing University of Aeronautics and Astronautics
Evgeny Petrov University of Sussex