A study of the contact interface for compressor blisks with ring dampers using nonlinear modal analysis

The integrally bladed disks, also known as blisks, have been widely used in industrial turbomachinery because of their benefits in aerodynamic performance and mass reduction. Friction damping is considered as the major damping sources in turbomachinery. However, in blisks, the friction damping is negligible due to the lack of the contact interfaces. The friction ring dampers are one of the emerging external damping sources for blisks. In this paper, a full-scale blisk with a friction ring damper is studied, where a 3D contact element is used to compute the contact frictions. The blisk and ring damper is investigated using their damped nonlinear normal modes. The modal damping can be directly calculated and used to quantify the friction damping generated by the ring damper. The contact behaviour within the contact interface is further analysed. The nodes with initial gap show less damping ability. The separations within the contact interface are expected to be avoided to achieve a better damping performance.