| The need to increase the passive damping of lightly damped mechanical systems has prompted the present study of the dynamics of dry friction damped systems. Dry friction damping has received considerable interest from the designers of turbomachinery and aerospace structures as a means of suppressing free vibration, limiting structure response to forced excitation and improving the stability of potentially unstable systems.; In this thesis, several types of dry friction damped systems are considered. Single and multiple-degree-of-freedom systems under harmonic excitation are studied analytically using traditional, one harmonic techniques and non-traditional, multi-harmonic techniques. Results are compared with time integration results and with experimental results. It is found that frequency domain techniques can be very effective in studying the behavior of dry friction damped systems. In particular, it is seen that a substantial improvement in accuracy can be obtained by including higher harmonics in the analysis.; An examination of the ability of dry friction damping to suppress flutter in turbine and compressor blades is also performed. Single and multiple-degree-of-freedom models are used for the blade system and a crude model for aerodynamic damping is provided by negative viscous damping. It is seen that dry friction is only of limited effectiveness in the suppression of flutter. A detailed study of the single-degree-of-freedom system with negative viscous damping revealed that the system behavior is quite rich; unbounded motion, zero-amplitude motion, period-1 and period-n motions, beat-type oscillations and aperiodic oscillations all are possible. The type of response is found to depend strongly on initial conditions as well as on system and excitation parameters. |
