Problems with tapered beam (CBEAM) element

[EFLAamo]

Hello everyone,

I have defined a tapered beam and assigned it to a line element but when running the model I get Bulk Data error. Taking a closer look, the meshed model does not have PID for these elements, which I was hoping that would get automatically generated along the element. Looking at the PBEAML element I see that it supports the fourth row where I can modify the card to have DIM1(B) DIM2(B) etc. but my fear is that it is only within one sub-part of my line element, so it would be broken into several tapered sections, so before resolving to this forum I tried to mesh this line element as a single element but to no avail, the mesh refinement doesn't allow me to pick this line to specify number of elements.

Any suggestions on how I can tackle this problem is it "safe" to update the PBEAML property with the forth row and then assign 23 to PID of all of the involved elements?

Ultimately, I think this is an error that requires fixing and I should not be responsible for the card update afterwards after putting the information in the property window. (using latest version).

[John_Holtz]

Hi @EFLAamo 

I tried Inventor Nastran 2023.2 and 2024.2 and did not have a problem with either one. If you try my 2023 file and do a Generate Nastran, you should see the following:

• Multiple PBEAML commands, one for each beam element.
• Prop ID field (column 3) filled in with a value.

If either of those is missing in my test model, then .... I'm not sure what to try. (Probably related to using a comma for the decimal symbol or something like that which should not make a difference 🙂)

If my test model works but your model does not, please attach your model. (If a single part, attach the .ipt file. If an assembly, create a pack and go file with the option to zip it; then attach the zip file.)

About the mesh control, that dialog only selects CAD geometry, meaning solids or surfaces. It does not allow the selection of sketch lines. (I assume your beams are created from sketches.) Even if the dialog would select sketch lines, the dialog generally works to make a finer mesh. I do not know if it will make a coarser mesh on the selected geometry.

John