Research On Modeling And Response Prediction Of Blade Disc Structure With Contact Interface

Dry friction structure is a kind of damping and vibration reduction measure widely used in aeroengine blade disc structure.By artificially increasing the contact surface between blades or between blades and discs,the technology utilizes the dry friction phenomenon between the contact surfaces to make them consume energy in vibration,thus restraining the vibration of the disc structure.The remarkable non-linearity of dry friction phenomena and the uncertainty of relative motion behavior of contact interface make it difficult to design various dry friction damped structures.To this end,this paper carries out research on blade disc structure modeling and response prediction method with contact interface.The main work and conclusions are as follows:1.The basic methods of structural modeling and response prediction with contact interface are systematically elaborated,and the response prediction and analysis of simple structures with contact interface are realized.2.A new fast calculation method of Jacobian matrix is proposed,which can improve the speed of predicting the steady-state vibration response of structures with contact interfaces by more than 800 times based on harmonic balance method.Compared with similar methods available in the world,the new algorithm has significant advantages in computational efficiency and generality.3.Based on the simplified model of underplatform damping structure,the influence of centrifugal force,mass of underplatform damper,exciting force,inclination angle of underplatform damper and rotation of underplatform damper on the vibration reduction characteristics of underplatform damping structure is analyzed.4.Applying the above contact interface modeling and response prediction methods to the real blade disc structure,and combining modal synthesis method and degree of freedom reduction technology,the fast response prediction of the blade disc structure finite element model with contact interface is realized.The results show that the fast response prediction method of the finite element model of blade disc structure with contact interface established in this paper has good accuracy,and has great advantages in calculation efficiency.It can provide a powerful tool for subsequent design and optimization of various types of dry friction dampers.