Experimental analysis of shrouded blades with friction contact

Turbine blades are subjected to high thermal and mechanical loads. Damages at the blades are frequent causes for the failure of turbomachines. To reduce the vibration amplitudes and the resulting dynamic stresses, friction damping devices are widely used. Because of the relative displacements in the contact between the friction damping devices and the blades, additional damping is generated due to energy dissipation.

At simulations a close description of the forces in the friction contact and a mathematical implementation of the mechanical contact model is necessary to optimize the friction damping devices. In this paper experimental measurements of heated blades coupled by tip shrouds are presented. The application of the calculation method to experimental measurements gives an insight in the influence of the temperature towards the contact parameters, especially the coefficient of friction. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)