PrePoMax (CalculiX FEA) - Tutorial 35 - Modal dynamics - mass-spring-damper system

PrePoMax is an open-source pre- and postprocessor for (also open-source) finite element analysis solver CalculiX. It's extremely user friendly and doesn't even require installation. PrePoMax can be used only on Windows.
In this tutorial I would like to show you how to perform a modal dynamics analysis of a mass-spring-damper system subjected to impulse force.
Geometry in step format and Scilab script: drive.google.c...
PrePoMax homepage: prepomax.fs.um...
Scilab homepage: www.scilab.org/

[@MrRenatopepin]

Amazing stuff as always, sir. Keep them coming

[@Toni-yl4hc]

Great tutorial of such a great feature of Prepomax 👏👏

[@rogerbergua6268]

Awesome tutorial! I'm wondering if instead of defining data points for the input load, you could use an input file with a time serie.

[@FEAnalyst]

There's no option to read the amplitude data directly from a file but you can just copy it and paste to the table if it's formatted properly.

[@setsototitipana8433]

Very great video, LOVE YOUR WORK
By any chance you could make a video about wave propagation in structure like in ultra sonic test? you have a structural member like a rod for example. one end of the rod is excited and the energy propagates through the structure and the response of the other end of the structure is record. It seems like it could be done using modal superpositoon like in the video but am not sure

[@FEAnalyst]

Thanks. I would use implicit or explicit dynamic analysis for that. This is a common benchmark for explicit solvers. I have a video about explicit dynamic analysis of a bar impacting a rigid wall but I will consider showing something like you described. It could be also used to show the concept of a stable time increment.

[@setsototitipana8433]

@@FEAnalyst Thank you, I would really like to see that. Meanwhile I will look at the video about the explicit dynamics to get a sense of how I would go about setting up the problem using that technique.

[@xzarrandiko]

Congratulations!

[@jakubsobka2621]

...of "kurua" what?

[@jakubsobka2621]

there's no fuucking way to run solver with modal dynamic step steady dynamic step or freqency step wothour just dynamic step output...?
isn't it?

[@jakubsobka2621]

Tymi razem grafika-montażyste oceniamy tylko na 2+ bo nawet czasu na zegarach nie skorygował u wszystko szybko rzuciło się w oczy 🥱

[@marcobatisti5252]

Very nice!!! Can you please share the .inp input file for calculix analysis? Thank you very much and keep pushing💪

[@FEAnalyst]

You can find the input file here: drive.google.com/file/d/1yZ7j590tZK4TAzluo8rFRVqbZ78udRS-/view?usp=sharing

[@toshibamaster2210]

to do the same for a 2D cantilever beam with delamination near the fastening?

[@FEAnalyst]

Modal dynamics analyses are linear, they don't support changing contact conditions. You would need dynamic implicit step for that.