Expansion of B31 elements with pretensions

Hello dear CalculiX community,
I’be been trying to set this model up with *PRE-TENSION on a 1D beam element (B31). One of the error messages is:
*ERROR in gen3dfrom1d: element X is a linear beam element with circular cross section Please use quadratic elements for beams with circular cross section.
But when I change to the B32 elements, I get the following:
*ERROR reading PRE-TENSION SECTION: element X is not a linear beam element
Has anyone experienced this before?

Try with a rectangular cross-section. The beam element used for pre-tension is deleted and replaced with MPCs anyway.

right, it can be replaced by rectangle sections as provide in official example. but required pre-calculation of beam width/height dimension based on equivalency of areas. direct way defining by it’s diameter could be better.

can it be more specific, solver versions and operating system?

i’m using latest versions on windows OS, simple changed section type from rect to circ above input examples is not a problem here.

also someone out there reported similar succeed to solve.

i checked again by rerun varying models, linear beam element only for easiness defining pretension.

it’s a dummy, the section and dimension are for completeness purpose. changing the type and values will not lead any differences in result.

You read my mind, that’s what I did, and it worked. Just catching up now. Thank you!

Yes, much easier.

I ran Pastix and Pardiso on 2.18 in Ubuntu and 2.20 Pastix on Windows… They all fail in the analysis, so I need to debug this model more, but I think the pretension part is now working with the RECT workaround.