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How to add unbalanced masses to a shaft?
Posted 29 feb 2024, 05:12 GMT-5 Computational Fluid Dynamics (CFD), Physics Interfaces, Structural Dynamics Version 6.2 2 Replies
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Dear all,
I am working on the COMSOL case "Whirling of Uniform Shaft Under Gravity" (URL:https://www.comsol.com/model/whirling-of-uniform-shaft-under-gravity-43541).
I would like to add unbalanced masses to the shaft to see the effect on the behavior of the shaft.
I do not want to change the structure of the rotor. How can I add a tiny unbalanced mass to the shaft without changing the shaft structure?
Many thanks in advance.
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I would suggest that you add the unbalance force directly as a co-rotating point load, e.g. 
, where 
, 
, and 
are the unbalance mass, eccentricity and rotational speed, respectively.
Frederik Wagner
COMSOL
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Alternatively, you could add a Disk feature, having a radial offset and zero moment of inertia.
-------------------Henrik Sönnerlind
COMSOL