Shrink-fitted joint behavior using three-dimensional solid finite elements in rotor dynamics with inclusion of stress-stiffening effect

Abstract

In this article, the contact behavior of a shrink-fitted joint in a rotor assembly at different spin speeds is studied, using the three-dimensional solid finite element approach. A custom frictionless contact model is proposed and extensively tested by means of simulation. The theory for solving pre-stressed damped eigenvalue problem is presented and implemented, and the results are presented in Campbell diagram form. Two sample rotor assemblies are studied. In addition, experimental modal analysis results of a shrink-fitted joint with various interferences are presented and numerically studied. The reduction of the interference of the shrink-fitted joint due to centrifugal forces at high-speed operation as well as the contact status are updated at each rotational speed step. The inclusion of stress-stiffening effect is studied in detail. The comparison of the Campbell diagram results with the results obtained using a commercial finite element software (Ansys) shows a good agreement.

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A Modified Transfer Matrix Method for Modal Analysis of Stepped Rotor Assembly Applied in the Turbomolecular Pump

“…e rotor assembly with a shrink-fitted joint was studied using the three-dimensional solid finite element approach. Meanwhile, the contact behaviors of various interference at different rotational speeds were analyzed [30]. ese references focus on the interference fit of the rotor assembly and stiffness contributions of the other assembling modes, such as clearance fit and screw joint, are not considered.…”