Vibration Analysis Of Aero-engine Considering Connecting Stiffness And Damping

At present, the vibration is a severe problem during aero-engine's Research and Design (R&D), how to reduce the vibration, how to improve the engine's stability and reliability when operated in a complex conditions, the engine designers must face.Bolted joints and coupling units are the two most commonly connection parts on aero-engine. Their connection stiffness and damping effects of vibration on aero-engine has not attracted people's attention. In this paper, the author has studied the effect on vibration of engine, considering the stiffness and damping of these two parts. First, according to the existing data, the author improved the method of calculating stiffness and damping of the bolts and coupling, and finally prepared a bolt stiffness calculation program, and achieved a fast calculation of stiffness of the coupling units in all directions. After analysis of a large number of studies at home and abroad, the author proposed an effective way to establish a simplified machine model, especially for such a thin-walled shell casing. This paper also presents an effective method of model simplification about bolts and coupling units, and verified the reliability of the model through testing. Finally the simplified model was introduced into the whole body vibration model. Verified through testing, this paper presents a general model validation process: Based on the classical theory, this paper introduced one or more element types and established a model which can simulate the actual aero-engine structure. In order to verify the reliability of the elements in this model, a set of model experiments are conducted. This process can lay the foundation for structural design and simulation of the whole body vibration of aero-engine.Chapter five in this paper is based on previous chapters, a whole body vibration of aero-engine model was perfected in this chapter. Through a variety of kinetic analysis, we concluded that: Bolt joins and coupling units are important parts in engine structure. Their connection stiffness and damping effect the vibration of aero-engine directly. SHELL elements and MATRIX elements have an irreplaceable advantage of thin-walled shell structure in a Finite Element Model (FEM).