transform constraint example

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bernd
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transform constraint example

Postby bernd » Thu Jan 26, 2017 10:26 am

I downloaded the transform constraint example from here: viewtopic.php?f=18&t=17127#p135715 applied a new material Calculix-Steel and a new Solver calculix. But the transform constraint seam not to work?

bernd
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transform01.fcstd
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KgoaOT
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Re: transform constraint example

Postby KgoaOT » Fri Jan 27, 2017 6:14 am

@Bernd,
Transform.PNG
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you have applied the constraint incorrectly.

please find attached the example file.
TransformBernd.fcstd
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the link to the calculix manual: http://feacluster.com/CalculiX/ccx_2.10 ... de289.html
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bernd
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Re: transform constraint example

Postby bernd » Fri Jan 27, 2017 9:21 am

works great. It was wrong in the downloaded file. Propably because the transform object was changed during develpment circle. I missed to set this to cylitrical.

thanks very much !
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bernd
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Re: transform constraint example

Postby bernd » Fri Jan 27, 2017 5:10 pm

Ok it works with the posted example, but not if I would like to do it completely new. Attached another example.
rotational_beam.fcstd
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KgoaOT
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Re: transform constraint example

Postby KgoaOT » Thu Feb 02, 2017 5:53 am

@Bernd,

it gives unsatisfactory results when I use the "Fusion001" geometry, when I switch to the "Fusion" geometry is works fine.
rotational_beamBernd.fcstd
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bernd
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Re: transform constraint example

Postby bernd » Thu Feb 02, 2017 6:43 am

KgoaOT wrote:@Bernd,

it gives unsatisfactory results when I use the "Fusion001" geometry, when I switch to the "Fusion" geometry is works fine.

rotational_beamBernd.fcstd
I may found the culprit. If the GMSH mesh object is used and the mesh is done inside the active analysis, than analysis group meshing is active which gives blind fast inpurt file writing, but there seams to be some bug with this group meshing and the transform constraint. If the mesh is meshed outside the analysis I get good results in any case for GMSH meshes too. I need to have a look at this. May be I simply make a property to bre able to manually deactivate the analysis group meshing.

Thanks for the help ! cheers bernd :D
rotational_beamBernd4.fcstd
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bernd
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Re: transform constraint example

Postby bernd » Wed Jul 22, 2020 6:11 am

the pic above shows a max deflection of 1.00352 mm. Let's do some calculations ...

rectangle cross section
width = 10 mm
height = 20 mm
overall length = 200 mm
span length = 180 mm (between center of cylinder holes)
q = 100 N/mm (100 N/mm / 10 mm width = 10 N/mm2 = 10 MPa Pressure on the face)
E = 210000 N/mm2

Deformation:
max f = (5 / 384) x (q x l^4) / (E x I)
I = w x h^3 / 12

max f = (15 / 96) x (q x l^4) / (E x w x h^3)

max f = (15 / 96) x (100 x 180^4) / (210000 x 10 x 20^3)

max f = 0.973 mm deformation in z-direction. The max overall deformation will be slightliy more :D
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bernd
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Re: transform constraint example

Postby bernd » Wed Jul 22, 2020 7:11 am

Attache the model updated. Furthermore the fusion was refined.

rotational_beamBernd5.fcstd
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screen.png
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bernd
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Re: transform constraint example

Postby bernd » Wed Jul 22, 2020 7:25 am

Stress:

max sigma_xx = M / W

W = w x h^2 / 6

M = q x l^2 / 8

max sigma_xx = (3 x q x l^2) / (4 x w x h^2)

max sigma_xx = (3 x 100 x 180^2) / (4 x 10 x 20^2)

max sigma_xx = 607.5 N/mm2 (Analysis gives 600 N/mm2 on bottom and 603 on top which is around 99 % :D )



screen.png
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Sudhanshu
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Re: transform constraint example

Postby Sudhanshu » Wed Jul 22, 2020 12:22 pm

bernd wrote:
Wed Jul 22, 2020 7:25 am
Stress:

max sigma_xx = M / W

W = w x h^2 / 6

M = q x l^2 / 8

max sigma_xx = (3 x q x l^2) / (4 x w x h^2)

max sigma_xx = (3 x 100 x 180^2) / (4 x 10 x 20^2)

max sigma_xx = 607.5 N/mm2 (Analysis gives 600 N/mm2 on bottom and 603 on top which is around 99 % :D )
Great!
Did you use Elasticity equation to solve this with Elmer?
Cause I got some very wrong results when I tried to do it.