modal analysis

[Bronco23]

Hi specialists

after I performed a modal analysis with 5 instances (respectively parts) and the first ten modes, I would like to know if it's just visually possible (via visualization) to understand which instance or which combinations of instances are responsible for which modes.
Summary:
Is there a way to get to know, which instances are responsible for which modes?

Greets

 

[corus]

Have you tried looking at the mode shapes under the deformed plot?

Tara

http://tinyurl.com/4ydjg7m

 

[mechfeeney]

If you run the analysis (right click submit under your job name) and then view the results (right click results under your job name), you will see the the visualization gui. In the near upper right hand corner of the screen you will see a rewind play and fast-forward button. This will toggle you through the different mode shapes. As corus explained...the mode shapes help to determine which area of the structure experiences the excitement.

gl hf.

 

[mechfeeney]

The text in the lower left of the visualization gui explains the mode (1,2,3 ....10) and natural frequency of that particular mode.

 

[Bronco23]

Thanks for those answers!
What's the difference between natural frequency and modes?

I think i didn't explain the question that good. I know how to visualize the seperate modes. My assembly has 5 instances. I guess every assemblymode has its own main-activator (1 out of these 5 instances). So with my visualisation its hard to understand which instances are responsible for that one mode. Because the construction-instances are very similar.
Is there another way apart from the visualisation to get to know which instances are the main-activator for each assembly-mode?

Greets

 

[johnhors]

"What's the difference between natural frequency and modes?" - each mode has a mode shape and an associated natural frequency (the eigenvector and eigenvalue).

You are performing modal analysis of the structure as a whole, there is no such thing as a "main-activator". The eigen solver does not "see" five instances, it just sees a single structure with stiffness and mass properties, nothing more, and solves the eigen problem for that single structure.

Each instance will probably have local modes where the other instances are doing very little, but that would happen inside a single instance model in local areas as well.

http://www.Roshaz.com

quality, cost effective FEA solutions

 

[Bronco23]

that was very helpful!