Study On The Influence Of Bolted Joint On The Dynamic Characteristic Of Rotor Structure

Rotor is a main structure of aero-engine, the dynamic characteristics directly influenceon performace and working reliability of aero-engine. Bolted structure is widely used onaero-engine structure by simple and good connection, but on rotor structure, experienceformula is widely used on boled structure design, a lack of thorough research on stiffenss anddynamic characteristics isn’t realized in recent years. With the development of computer andfinite element technology, more and more attention has been paid on bolted structure anddynamic characteristics.At first, the contact of bolted structure has been studied, the factors of which affectnormal contact stiffness has been obtained. the calculated results were compared and analyzedwith the modal test results, and the results obtained from the method which used in thesimulation agrees well with the experiment results. The study show that the dynamics ofbolted structure were accurately simulated by finite element method. Then the bolted structureparameter(such as flage thickness, height, fricition coefficient) sensitivity analysis werecarried by using the finite element method.The bolted pretension affect modal frequency was obtained by using finite elementmethod on calculating dynamic of bolted rotor structure. The reasonable value of boltedpretension was calculated during scope of work based on separation, strengh, fatiguestandards which determined on bolted pretension. Then some reasonable value was selected.Bolted pretension affect on rotor critical speed were calculated by Compbell diagram method,and the correctness was demonstrated by using transient method to simulate the accelerationof the rotor. Finally, the impact of dynamic of actual aero-engine which due to boltedpretension was studied by modeling and analysis turbine rotor of an aero-engine, and thesteady-state temperature field which affect rotor structure on dynamics was considered. Thenfurther steps to study bolted structure affect on rotor dynamic under a variety of load weremade.