Dynamic characteristics of the flange joint with a snap in aero-engine

As an important component in aero-engine, the stiffness of the flange joint has a direct impact on vibration characteristics. The paper studies the stiffness characteristics of the flange joint which includes a snap by nonlinear transient analysis in ANSYS. The angle of rotation-load curves under harmonic transverse load are obtained. It is discovered that there are different routes of curves in the process of uploading and unloading, and that the curves form a closed cycle, which is called hysteresis loop. Then, the paper also analyses the hysteresis’s generation mechanism and the influence of joint parameters — preload of bolts and interference of the snap — on the shape and area of hysteresis loop. Finally, a model, which is comprised of the three-dimension finite element (namely, the joint) and beam element, is built to study the influence of hysteresis on vibration. The results show that the hysteresis of joint can be aroused under the circumstance of certain vibration amplitude and that the hysteresis can rapidly accelerate the amplitude attenuation by the mean of energy dissipation. The research results can be applied to vibration suppression design of aero-engine. © 2018 International Institute of Acoustics and Vibrations. All Rights Reserved.