Blade couple with dry friction connection.

Vibration of a blade couple damped by a dry friction contact in the shroud is investigated by means of hysteresis loops and response curves analysis. The studied system is excited by one harmonic external force in a frequency range near to the lowest eigenfrequency of real blades. Blades are connected by means of a damping element consisting of dry friction part linked in series with linear spring. This ''stick-slip'' damping element is supposed to be either weightless or of a very small mass which models the mass of elastically deformed parts of contacting bodies near the friction surface. Two approximate mathematical models of ''stick-slip'' dry friction elements are suggested and analysed. The response curves of blade couple connected by stick-slip damping element are presented for different values of slip friction forces and two values of mass of elastically deformed parts. [ABSTRACT FROM AUTHOR]