Numerical and Experimental Study on Dummy Blade with Underplatform Damper

To confirm the variation in damping ratio offered by dry friction dampers against structural vibration stress, this study developed a blade vibration response test system for capturing damping characteristic curves through both frequency sweep excitation and damping-freevibration methods. The damping-free vibration method demonstrates high efficiency, allowing for the acquisition of a complete damping ratio characteristic curve in a single experiment. Experimental findings indicate that the two contact surfaces on the triangular prism damper produce distinct damping effects, closely aligning with the predicted damping characteristic curves. The peak damping ratio was found to be independent of the centrifugal load of the damper; dampers with varying contact areas produce approximately similar damping characteristics; and the damping effect shows a positive correlation with the root extension length.