VIBRATION ANALYSIS OF DRY FRICTION DAMPED TURBINE-BLADES USING SINGULAR PERTURBATION-THEORY

The dynamic behavior of a turbine blade with an attached dry friction damper is investigated. Due to the presence of both high and low frequ ency resonances, the system is numerically stiff and time consuming to simulate. Three reduced-order models that remove the numerical stiffn ess problem are developed using singular perturbation theory. Two of t hese models are developed for the case of small damper mass, and the t hird model is developed for the case of high damper stiffness. It is s hown that these models are consistent with two physically-motivated ap proximate models that have appeared in the literature. The accuracy of each approximate model is examined for a range of system and excitati on parameters through comparison with the original full-order model. I t is seen that inclusion of damper mass has a significant effect on th e blade system response.