if use m, the shape is right. The others all SI.This 25mm rod. Need to use CBAR.
But displacement is 8.35 um. You sure it is in mm?
A Mystran writer error when using 1d element
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Re: A Mystran writer error when using 1d element
Last edited by johnwang on Sat Sep 18, 2021 12:11 pm, edited 1 time in total.
Re: A Mystran writer error when using 1d element
does it means your section code only works with meter units?
Re: A Mystran writer error when using 1d element
in FreeCAD everything is in mm. AFAIK length units passed to pyNastran and thus to mystran solver from FreeCAD are in mm as well.
Re: A Mystran writer error when using 1d element
For Mystran all should be SI in case file or the American one.
I haven't tested Rect/Pipe, will try tomorrow.
I changed here at exportNastranMesh.py
I haven't tested Rect/Pipe, will try tomorrow.
I changed here at exportNastranMesh.py
Code: Select all
# nodes
kr=0.001
pynas_nodes = "# grid cards, geometric mesh points\n"
for node in femnodes_mesh:
vec = femnodes_mesh[node]
pynas_nodes += "model.add_grid({}, [{}, {}, {}])\n".format(node, vec.x*kr, vec.y*kr, vec.z*kr)
# print(pynas_nodes)
Re: A Mystran writer error when using 1d element
In the case file, if the mesh is in mm, the PBAR is calculated with m. They mixed up. So result will not be right.
Re: A Mystran writer error when using 1d element
no Mystran does not need SI units. Mystran will get you back what you have passed to him. I have asked this one to Mystran dev right at the beginning of coding and got repley from a dev. We in FreeCAD pass the same units as we pass to calculix solver. We pass mm and N, with this we get back stress in N/mm2 And thus we pass youngs mofulus in N/mm2. Thus your section code should pass all length units in mm and we will be fine.
See comments at the beginning of calculix writer in source code.
See comments at the beginning of calculix writer in source code.
Re: A Mystran writer error when using 1d element
post on the regard of units ... https://forum.freecadweb.org/viewtopic. ... 20#p517791
Re: A Mystran writer error when using 1d element
https://github.com/berndhahnebach/FreeC ... ry.py#L116
these lines need to read the data in mm. Than you are fine ...
with this fix in your code, I get 8.35 mm maximum deflection ...
https://github.com/berndhahnebach/FreeC ... b8f6a6b28c
these lines need to read the data in mm. Than you are fine ...
with this fix in your code, I get 8.35 mm maximum deflection ...
https://github.com/berndhahnebach/FreeC ... b8f6a6b28c