In this video tutorial for Salome-Meca 2017, I will show you how to do a modal analysis of a simple plate with Aster-Study!

Here’s what you will learn:

- How to model the plate and prepare the mesh
- How to use the ASSEMBLAGE function to generate the mass and rigid matrix.
- How to use the CALC_MODES function to perform a modal analysis
- How to vizualize the results with Paravis (animation)
- How to write the modal frequencies in a text file

If you want also to understand what is actually a modal analysis, you can check this other article from my blog:

If you like this video, could please help me by liking it? Thank you so much!

–Cyprien

**Any idea for the next tutorial you would like to see?**

Post a comment and let me know!

Kishore says

Hi Cyprien

I have been following your tutorials. they are very detailed. can you post a tutorial on how to do Frequency response analysis, especially for random vibration from a PSD profile.

Piero Ladisa says

Cyprien, be careful: in this tutorial you made a mistake in input data:

Code_Aster has no control on Units System, so in a modal analysis have to input data in coherent units. If you use a model in millimetres and forces in Newton, you are obliged to input mass data in tons and not in kg, for the coherence of the formulation F = m a. So density shall be in Ton/mm3, in this case 2.7e-09.

For all the remainimg, you did a grat job! ;)

Cyprien says

Hi Piero, Thanks! That’s indeed a mistake… I was more focused on showing the analysis process that I forgot about the basics of the choice of unit. I’ll have to add that as a note.

Piero Ladisa says

Great… I am preparing a beginner guide of code_aster in italian, I cite FEAforAll and directly some of your video tutorial, that are fundamental to learn this code… Ciao!

Cyprien says

That’s awesome, thank you so much Piero!

James says

Hi Cyprian,

Great tutorial as always.

Is it possible to make the .comm files available for download?

I like to run batch mode using ASTK. It would be good to see the comm files for working in this way.

Thanks again

Best regards

James

Cyprien says

Good point James, next time I’ll think about putting the .comm file here for download. It’s been some time I did this video, not sure I can find this comm file again…

Michele says

Very interesting tutorial. It would be very interesting also understand how make the calculation of acoustic modes of a 3d cube, like a room with rigid walls.