Session: 28-02 System Response / Blade-Tip-Timing

Paper Number: 125263

125263 - An Optimization Method for Stiffness and Damping Mistuning Identification From Blade Tip Timing Data 

System identification of dynamic properties is of large interest to the turbomachinery industry to create more accurate computational models and more effective designs. Previous identification techniques were able to accurately capture the blade variability, known as mistuning, in the stiffness as well as the average damping of all the blades. Mistuning is vital to identify and study because the symmetry of the system is broken and can lead to vibration localization and high amplitudes. In this work, a new method is proposed to not only capture the stiffness mistuning values, but also the blade-to-blade variability in damping. These damping mistuning values have been shown to have a significant effect on the dynamics of bladed disk systems. Incorporation of the damping mistuning into the computational model can be done utilizing an augmented component mode mistuning method with either structural or proportional damping. The mistuning values for this new identification method were compared to a well-established direct method and a previously studied optimization method. Blade responses were then found using time integration and the newly identified mistuning values, these were then compared to experimental tip timing data from full scale rotating experiments. These comparisons show that the new model is able to better reproduce experimental data using computational models that incorporate both stiffness and damping mistuning values.

Presenting Author: Troy Krizak The Ohio State University

Presenting Author Biography: Troy is doctoral candidate in the gas turbine laboratory at The Ohio State University studying under professor Kiran D'Souza.

Authors:

Troy Krizak The Ohio State University
Eric Kurstak GE Aerospace
Kiran D'souza The Ohio State University