Impact-Enhanced Resonant Vibration Absorber for Turbomachinery Blisks

Abstract The study of blisks is essential to the development of safe and efficient turbomachines. Blisks are geometrically complex structures exposed to high temperatures and pressures that operate at high rotational speeds, and thus are susceptible to fatigue. Therefore, reducing vibration amplitudes in blisks is paramount to avoid failure of these systems. This paper extends previous studies of blisk dampers based on tuned vibration absorbers by analyzing the effects of including energy dissipation through impacts. In this work, the absorber has a ring architecture that also allows impacts. A finite element model of an as-manufactured blisk with 22 blades is used throughout the analysis, and the damper is tuned for experimental operating conditions. Impacts are modeled microscopically, using a novel impact-contact characterization. Results show that impacts significantly enhance the blade response reduction through energy dissipation. Furthermore, impacts slightly increase shift resonant frequencies and are effective for specific combinations of contact surface geometry and material properties.