CalculiX contact surfaces

About the development of the FEM module/workbench.

Moderator: bernd

david.lambert
Posts: 1
Joined: Sat Oct 26, 2019 1:39 pm

CalculiX contact surfaces

Postby david.lambert » Sat Oct 26, 2019 3:05 pm

I need to solve a contact problem having slightly more complicated geometry than in this problem, but is essentially quite similar. Here I have made a corner out of three fixed blocks. The fourth block is supposed to move into the corner and stop. Here's my CalculiX input file. What should it be so as to converge on the reasonable solution?
Thank you.

*NODE, NSET=Nmesh
1,0.000000000000e+000,0.000000000000e+000,-1.000000000000e+000
2,1.000000000000e+000,0.000000000000e+000,-1.000000000000e+000
3,0.000000000000e+000,1.000000000000e+000,-1.000000000000e+000
4,1.000000000000e+000,1.000000000000e+000,-1.000000000000e+000
5,0.000000000000e+000,0.000000000000e+000,0.000000000000e+000
6,1.000000000000e+000,0.000000000000e+000,0.000000000000e+000
7,0.000000000000e+000,1.000000000000e+000,0.000000000000e+000
8,1.000000000000e+000,1.000000000000e+000,0.000000000000e+000

9,-1.000000000000e+000,0.000000000000e+000,0.000000000000e+000
10,0.000000000000e+000,0.000000000000e+000,0.000000000000e+000
11,-1.000000000000e+000,1.000000000000e+000,0.000000000000e+000
12,0.000000000000e+000,1.000000000000e+000,0.000000000000e+000
13,-1.000000000000e+000,0.000000000000e+000,1.000000000000e+000
14,0.000000000000e+000,0.000000000000e+000,1.000000000000e+000
15,-1.000000000000e+000,1.000000000000e+000,1.000000000000e+000
16,0.000000000000e+000,1.000000000000e+000,1.000000000000e+000

17,0.000000000000e+000,-1.000000000000e+000,0.000000000000e+000
18,1.000000000000e+000,-1.000000000000e+000,0.000000000000e+000
19,0.000000000000e+000,0.000000000000e+000,0.000000000000e+000
20,1.000000000000e+000,0.000000000000e+000,0.000000000000e+000
21,0.000000000000e+000,-1.000000000000e+000,1.000000000000e+000
22,1.000000000000e+000,-1.000000000000e+000,1.000000000000e+000
23,0.000000000000e+000,0.000000000000e+000,1.000000000000e+000
24,1.000000000000e+000,0.000000000000e+000,1.000000000000e+000

25,5.000000000000e-002,5.000000000000e-002,5.000000000000e-002
26,9.500000000000e-001,5.000000000000e-002,5.000000000000e-002
27,5.000000000000e-002,9.500000000000e-001,5.000000000000e-002
28,9.500000000000e-001,9.500000000000e-001,5.000000000000e-002
29,5.000000000000e-002,5.000000000000e-002,9.500000000000e-001
30,9.500000000000e-001,5.000000000000e-002,9.500000000000e-001
31,5.000000000000e-002,9.500000000000e-001,9.500000000000e-001
32,9.500000000000e-001,9.500000000000e-001,9.500000000000e-001

*ELEMENT, TYPE=C3D8, ELSET=Emesh
1, 1, 2, 4, 3, 5, 6, 8, 7
2, 9, 5, 7, 11, 13, 14, 16, 15
3, 17, 18, 6, 5, 21, 22, 24, 14

4, 25, 26, 28, 27, 29, 30, 32, 31

*MATERIAL,NAME=STEEL
*ELASTIC
210000,0.3
*SOLID SECTION, Elset=Emesh, Material=STEEL

*nset,nset=fixed,generate
1,24

*boundary
fixed,1,3

**element 1 face 2 z
**element 2 face 4 x
**element 3 face 5 y
**
**element 4 face 1 z
**element 4 face 6 x
**element 4 face 3 y
*surface,name=mz
1,s2
*surface,name=mx
2,s4
*surface,name=my
3,s5
*surface,name=sz
4,s1
*surface,name=sx
4,s6
*surface,name=sy
4,s3

*CONTACT PAIR, INTERACTION=z, TYPE=Surface TO SURFACE
**slave,master
sz,mz
*SURFACE INTERACTION, NAME=z
*SURFACE BEHAVIOR, PRESSURE-OVERCLOSURE=LINEAR
10000000,0.1,0.01
*friction
0.3,1000000
*CONTACT PAIR, INTERACTION=x, TYPE=Surface TO SURFACE
**slave,master
sx,mx
*SURFACE INTERACTION, NAME=x
*SURFACE BEHAVIOR, PRESSURE-OVERCLOSURE=LINEAR
10000000,0.1,0.01
*friction
0.3,1000000
*CONTACT PAIR, INTERACTION=y, TYPE=Surface TO SURFACE
**slave,master
sy,my
*SURFACE INTERACTION, NAME=y
*SURFACE BEHAVIOR, PRESSURE-OVERCLOSURE=LINEAR
10000000,0.1,0.01
*friction
0.3,1000000

*STEP, NLGEOM, INC=200
*STATIC
*cload
32,1,-1e-8
32,2,-1e-8
32,3,-1e-8

*NODE FILE
U
*EL FILE
S
*CONTACT FILE
CDIS
*END STEP
User avatar
bernd
Posts: 8468
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: CalculiX contact surfaces

Postby bernd » Sat Oct 26, 2019 3:46 pm

Welcome to FreeCAD forum. Would you include code in code tags if you post code ... You can still edit your post in this regard. How do you created these input file. It seams not come from FreeCAD FEM?

Cheers bernd
Attachments
Screenshot_20191026_174430_.png
Screenshot_20191026_174430_.png (31.43 KiB) Viewed 494 times
fandaL
Posts: 342
Joined: Thu Jul 24, 2014 8:29 am

Re: CalculiX contact surfaces

Postby fandaL » Sat Nov 02, 2019 9:12 pm

david.lambert wrote:
Sat Oct 26, 2019 3:05 pm
I need to solve a contact problem having slightly more complicated geometry than in this problem, but is essentially quite similar. Here I have made a corner out of three fixed blocks. The fourth block is supposed to move into the corner and stop. Here's my CalculiX input file. What should it be so as to converge on the reasonable solution?
Thank you.
I'm not experienced in tuning contact parameters, but my results show that using only one slave and one master surface converges in this case, probably since they are continuous surfaces.

Code: Select all

*surface,name=master_all
1,s2
2,s4
3,s5
*surface,name=slave_all
4,s1
4,s6
4,s3

*CONTACT PAIR, INTERACTION=z, TYPE=Surface TO SURFACE
**slave,master
slave_all,master_all
*SURFACE INTERACTION, NAME=z
*SURFACE BEHAVIOR, PRESSURE-OVERCLOSURE=LINEAR
10000000,0.1,0.01
*friction
0.3,1000000
contact_cubes_disp.png
contact_cubes_disp.png (11.36 KiB) Viewed 372 times