## Calculate the whirling/critical speed of a shaft

## Calculate the whirling/critical speed of a shaft

(OP)

I was asked to calculate the critical speed of a complex shaft with blades (for an helicopter) and since I've never done it before I'm doing a smaller model with a beam and a lump mass at the end. I have the equation to calculate its critical speed so I can double check with ABAQUS.

The problem is that I don't know how to calculate this value through ABAQUS. Any idea? It's a direct-Solution steady-state dynamic analysis and I read already the documentation but I'm missing something I guess.

Thanks!

The problem is that I don't know how to calculate this value through ABAQUS. Any idea? It's a direct-Solution steady-state dynamic analysis and I read already the documentation but I'm missing something I guess.

Thanks!

## RE: Calculate the whirling/critical speed of a shaft

## RE: Calculate the whirling/critical speed of a shaft

## RE: Calculate the whirling/critical speed of a shaft

## RE: Calculate the whirling/critical speed of a shaft

Also, is there a way to get Campbell diagram via ABAQUS or I have to create them by changing the input value of rpm?

Thanks!

## RE: Calculate the whirling/critical speed of a shaft

Unfortunately Abaqus won’t generate Campbell diagram automatically and you have to create it by running several analyses with different rotation speed.

## RE: Calculate the whirling/critical speed of a shaft

I created a static with Rotordynamics load, a modal analysis and complex analysis. With animation one I can see the whirling.

## RE: Calculate the whirling/critical speed of a shaft

## RE: Calculate the whirling/critical speed of a shaft

If you search for "Rotordynamics Analysis

using Abaqus/Standard" you will find a nice document with example of such analysis.