Contact model identification for friction ring dampers in blisks with reduced order modeling

Abstract

Friction dampers are commonly used to attenuate blade vibration to acceptable levels in turbomachinery. Friction interfaces significantly affect structure responses by inducing localized nonlinear stiffness and damping changes. Thus, detailed contact interface modeling is essential to ensure reliable numerical modeling. Accurate contact models that describe the behavior of friction interfaces often require parameterized contact properties that can be identified from vibration tests. Unfortunately, direct measurements of spatially distributed forces transmitted between contact surfaces are often not available. This paper proposes a methodology for identifying contact parameters using system-level response measurements. An efficient reduced order model (ROM) is introduced in the identification process to predict the responses of a bladed disk with a friction ring damper. The system responses obtained in the time domain are adopted as surrogate data for identification. The ROM is shown to have a good performance in predicting forced responses with less than 0.1% relative error at the resonance frequencies. Contact parameters of the frictional interfaces are identified by minimizing the difference between the system responses in the time domain and the predictions from the ROM.