Studies On Vibration Characteristic Of Aero-engine Rotor With Bolt Joint

Bolt joint structure is simple,easy to apply,easy to setup and has a solid stiffness,so it is widely used in joint structures of aero-engine.Due to the complex working environment,bolt joint may be loosen and failure by fatigue.The nonlinearity in bolt joint itself will also bring a relative complex motion to rotor.What is more,it is imperative to conduct a parametric and a detailed modeling work on aero-engine.As an important structure,a parametric work on bolt joint is indeed.Based on pioneers’ work,this article carry on a research on rotor system with bolt joint,including a structure dynamics research with the method of finite element simulate,especially a detailed work on nonlinear steady response.The works and results of this article is as follows:1.A detailed work on characteristic of deformation force in different directions of bolt joint is developed.A parametric model is given in axial,radial and bending directions.In such directions,deformation force model is also talked about in a shell with bolt joint.2.In order to getting close with a real aero-engine’s rotor,a shell rotor with bolt joint is designed.Applying Workbench,some conclusion is came up with by the analysis on the Campbell diagram and Displacement nephogram,the influence that bolt joint has on critical speed is also found.3.Following the work of finite element simulating,a simple model of rotor is made and nonlinear steady response of the model with bolt joint is conduct with numerical method.The relation between pretightening force and motion of rotor is found,and it is the degree of bend in rotor has an important influence on the dynamics of rotor.The reason of complex motion at 2rd critical speed is also explained.4.Based on the Genetic Algorithm,a method of identifying the bend stiffness of rotor with bolt joint is also designed.A comparison of identification result under different noise is conduct,and such a method perform a good robustness under different noise.This article has a good achievement on research of nonlinear dynamics of aero-engine rotor with bolt joint,and can be a guide of research on the influence that bolt joint has,on the rotor dynamics.