Dynamic Modeling and Projection-Based Reduction Methods for Bladed Disks With Nonlinear Frictional and Intermittent Contact Interfaces

Turbine bladed disks or blisks, which constitute critical components of most modern turbomachinery, are known for their complex vibratory behavior. The nonlinear dynamics observed in most operational regimes of blisk with contact interfaces are dominated by one of two typical contact behaviors. Frictional contacts are dominated by Coulomb friction forces, while intermittent contacts are characterized by multiple separation events. Other factors such as the dispersion in material or geometric properties across blades, known as mistuning, also affect the dynamics significantly. Presently, probabilistic analysis is the widely accepted design methodology to account for mistuning, which is unknown prior to manufacture. Thus, reduced order modeling of these blisks is essential as high fidelity models are prohibitively expensive for such simulations. This paper provides a technical discussion of dynamic modeling and reviews projection-based techniques used for creation of reduced models of blisks with contacts.