I am trying to model the force of a motor on a central pipe [hexagon and cylindrical] along with some disks.
I would like to see how many pascals it would take for any of the parts to reach failure. I am using standard medium carbon steel, I've attached two files they both have a gmsh with a max size of 1.00000000 mm so it might be a bit slow to open.
I'd like to see what's the maximum radial torsion I could apply to a gear connected to the shaft at the three different sections. I would also like to see how I can do the same for the hexagon hole in the inner disk as well as the six holes that would hold more stabilizing pins going horizontally.
Actually the files are too large to attach with the gmsh and analysis. I'll add the files without gmsh and analysis.
Would anyone be able to guide me through applying a rotational torsion to the pipe to see where they will break?
OS: Ubuntu 17.04
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FreeCAD FEM moment of inertia & axial torsion
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FreeCAD FEM moment of inertia & axial torsion
- Attachments
-
- pipe.fcstd
- (43.91 KiB) Downloaded 83 times
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- disk.fcstd
- (30.04 KiB) Downloaded 76 times
Re: FreeCAD FEM moment of inertia & axial torsion
Dear blubee,
I am not sure if applying rotational load does work at the moment... Please see also https://forum.freecadweb.org/viewtopic.php?f=18&t=23778 there you find also some further information in the listed links.
But you can simply create a test case.
Regarding the size of the model you should consider simply deleting the mesh information by right clicking on the mesh object. One can than still remesh your model with the all stored settings.
BR,
Howil
I am not sure if applying rotational load does work at the moment... Please see also https://forum.freecadweb.org/viewtopic.php?f=18&t=23778 there you find also some further information in the listed links.
But you can simply create a test case.
Regarding the size of the model you should consider simply deleting the mesh information by right clicking on the mesh object. One can than still remesh your model with the all stored settings.
BR,
Howil
Re: FreeCAD FEM moment of inertia & axial torsion
Thanks, with that I attempted to do a little test. Would anyone be willing to take a look at this results file?HoWil wrote: ↑Mon Aug 21, 2017 5:49 am Dear blubee,
I am not sure if applying rotational load does work at the moment... Please see also https://forum.freecadweb.org/viewtopic.php?f=18&t=23778 there you find also some further information in the listed links.
But you can simply create a test case.
Regarding the size of the model you should consider simply deleting the mesh information by right clicking on the mesh object. One can than still remesh your model with the all stored settings.
BR,
Howil
https://filetea.me/n3wU1YLHUMpSPOYoV6TSFLh1Q
I am trying to figure out how to get the data that I need.
There are constraints on both ends of this pipe, then there's force applied [500] is that MPa? Then after a little while I get the result which looks like this: when I animate the displacement it gets really strange results: I just want to know what's the MPa that would cause any part of this model to fail.
When applying force, it only asks for a number; is that Newtons, N.M, N.M^2, MPa, ft-lbs, etc?
Re: FreeCAD FEM moment of inertia & axial torsion
Are you talking about this input box? As you can see, there is asked for an "area load". Load's unit is Newton. This load will be distributed equally to selected face.
BTW this issue is on the run:
Re: FreeCAD FEM moment of inertia & axial torsion
Well that doesn't look good on me, but i am learning. I'm a programmer first, fell into physics sorta out of necessity.
Thank you for the clarification.
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Re: FreeCAD FEM moment of inertia & axial torsion
EDIT 21.08.2017 (UR_, I am getting older... )
Hello blubee,
according to the above formula from UR_ for calculating shear-stress under torsional loading, you can
apply a torsion-loading of 0,231 kNm at the 20 mm transmission (when using steel S235 with a maximum
allowable shear stress of 136 MPa). The distance between the holes in the disk and the axis of the transmission is 30 mm,
so you must apply a load of 7100 N at both holes to get the Torsion of 0,231 kNm at both ends of the transmission.
If you run the calculation with your modell, you will get good results (plot: shear-stress). Attached is the modell
with the cleared mesh (doubleclick on mesh, mesh it hyperfine as you did before and have a pizza during ccx-run... )
regards thomas
Hello blubee,
according to the above formula from UR_ for calculating shear-stress under torsional loading, you can
apply a torsion-loading of 0,231 kNm at the 20 mm transmission (when using steel S235 with a maximum
allowable shear stress of 136 MPa). The distance between the holes in the disk and the axis of the transmission is 30 mm,
so you must apply a load of 7100 N at both holes to get the Torsion of 0,231 kNm at both ends of the transmission.
If you run the calculation with your modell, you will get good results (plot: shear-stress). Attached is the modell
with the cleared mesh (doubleclick on mesh, mesh it hyperfine as you did before and have a pizza during ccx-run... )
regards thomas
Last edited by thschrader on Mon Aug 21, 2017 7:23 pm, edited 1 time in total.
Re: FreeCAD FEM moment of inertia & axial torsion
That's right.thschrader wrote: ↑Mon Aug 21, 2017 6:44 pm dann kannst du beim Rechenlauf in Ruhe eine Pizza essen...
But can you please translate this to english.