Research On Vibration Characteristicof Shrouded Bladed Disk With Friction Damper

Along with the development of aviation industry, the requirements such as the ratio of sages of engine become higher and higher. It makes the design requirements in material and structure of engine more important. Turbine blades work in high temperature and high pressure air, its vibration can cause structure fatigue and fracture easily. It’s a good way to use friction damping structure to control the blades’ vibration. Structures such as integral shroud, shoulder and listrium are not only simple, but also effective. it’s very important in making deeper studies on vibration characters of blades and bladed disk, and researching the rules of friction damping structures such as shrouded blades in decreasing resonance amplitude and changing resonance frequency. The result process important theory and application value in engineering.In this paper, finite element method is used. The research is based on three-dimensional two-bar(Blade to Blade) slipping model, and vibration response analysis program of bladed disk is written. Different models are calculated to analyze the effective rules of different parameters. The vibration characters of shrouded blades and bladed disk system under new friction model are studied. The main contributions of the paper are:(1)Based on the three-dimensional macro-micro slip model, the friction model is developed from one-bar(Blade to Ground) model to two-bar model.(2) Equivalent damping scheme with square damping is used to introduce nonlinearity factor. The new equivalent stiffness and damping are got and be used in the program.(3)The vibration response analysis programs for different blades and bladed disk are developed, by using the APDL and VC++ language. Different shrouded blades are analyzed as examples to get their vibration characteristics.(4) The experimental program is improved by using vibration measurement with laser to test the 45°zigzag-shrouded blades. The testing precision is improved, and the characteristic of the vibration with friction damping is gained to provide the reference for theoretical calculation.(5)Finite model for the cyclic symmetry structures is established, and the method of “Duplicate Sector” is used to solve the harmonic vibration response. Make the corresponded program to calculate the vibration response for the blades with the zigzag- shrouded blades, and analyze the vibration characteristic of 45°zigzag-shrouded bladed disk.