Hi all
As part of my internship, I have different bent sheet metal parts (sometimes welded as well) whose thickness needs to be changed. These parts are essentially subjected to tension and bending.
I would like to do a finite element analysis to see if I can determine a lower plate thickness than the current one, which would be acceptable from a mechanical point of view.
I have at my disposal the stp files of these parts (which were drawn in NX), which seem to be in volume. I had started to rework the thicknesses by creating new volumes and subtracting them with the Boolean operations.
But by talking with teachers at my school, I understood that for finite elements with Catia and/or Abaqus, it is preferable to work in surface because my thickness is small compared to the other dimensions.
Problem, I don't know how to work in surface from my original stp file. Is it possible to transform them by manipulation, by selecting the average thickness for example or by taking the surfaces at the ends?
I'm relatively new to Catia so don't hesitate to detail a little if the manipulations are a bit complex!
Thank you:)
Kind regards
Adrien
Hello
You can work in surface from a (solid) geometry from a STEP or even from a CATIA file.
It is important to keep in mind that what you are going to " extract " or " disassemble " has no history (no curve or construction elements).
Disassemble: I don't recommend too much (the number of surfaces can be very important).
Extract : we will use the function to retrieve surfaces, edges of surfaces, to cut, etc.
Depending on the license you have (GSD), and the version of CATIA (I believe superior to R22).
The Surface Midfields command should help you.
If below the first commands to learn (If you have installed the CATIA doc) we select the command then F1 to open the help on this command.
Hello Franck,
Thank you for your answer.
If I understand correctly, I would have to select the surface of the medium before extracting it?
In any case, when I select the middle surface of a piece of my room, I get an error message "the selection is denied to prevent an update cycle. The selected body must not contain a surface in the middle"
Thank you!
You have to select the middle surface command and then point to the pairs of opposite surfaces so that Catia calculates the "middle" surface (you can change the ratio 0.5).
I have attached the catia help page.
Edit: do you work in hybrid mode?
surface_milieu.pdf
Ok great I understood, thank you very much!
I have no idea what hybrid mode is.
Hello
Catia's "Hybrid" mode when activated gives rigor to the organization of elements such as plane stitch, line, surf, etc.
Their position in the specification tree is chronological.
For example, the parent point of a plane (parallel to a point) cannot be moved after the plane.
These elements can be arranged in ordered geometric sets (green) or appear in the parts bodies in the order in which they were created.
In our country, this mode is not accessible.
Hello
To tell the truth, I don't know if it's activated, I don't really have a tree since I got a stp file.
My first task was to create solids and subtract them by Boolean operations in order to change my thickness, until I was told that working in surface area would be better for FEM calculations.
When you create a new file ( file / new / part) in the window that opens (previous screenshot) if the box is checked (orange) you work in hybrid if not you work in normal mode.