1. Jiangsu Provincial Key Lab of Aerospace Power System, School of Energy and Power Engineering, Nanjing University
of Aeronautics and Astronautics, Nanjing 210016, China;
2. University of Sussex, Brighton BN1 9QT, United Kingdom
Abstract：A method was developed to analyze modal damping factors of a blade with root dry friction contact. Aiming at the dry friction problem at blade root, the blade root high fidelity model with contact was used to calculate modal damping based on the energy-dissipating principle. It was shown that the developed method consists of 3 parts including in the finite element software ANSYS, adopting the contact element describing surface-to-surface friction contact interaction to establish the blade root high fidelity model with dry friction contact; performing the modal analysis for the built blade root model and simulating forced vibration of the local blade root model under simple harmonic excitation in transient analysis module; calculating modal damping factor according to dissipation energy generated by micro-slip dry friction on blade root contact surface. The developed method could be used to predict modal damping factors of blades with root dry friction damping under different modal shapes. The actual blade model with contact surface was used to verify the developed method, and effects of amplitude, rotating speed, friction coefficient, normal and tangential contact stiffnesses on modal damping factors under different modal shapes were analyzed.
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