Nonlinear Vibrations with Friction: A Multiharmonic Approach

Turbine blades are subjected to vibrations caused by static and dynamic loads. To avoid damage, the arising dynamic stresses can be reduced by generating friction contacts between the blades leading to additional damping. The resulting nonlinear equations of motion of the blade dynamics can be solved by the Multiharmonic Balance Method (MHBM), which is described in this paper. With the MHBM, it is possible to consider a multiharmonic excitation as well as a response consisting of several harmonics. In this paper, the MHBM is applied to both a simple 1 DOF nonlinear oscillator and a cyclic model of a blade integrated disk (blisk). (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)