# Tabular contact **URL:** \ **Category:** Uncategorized\ **Created:** [December 27, 2022, 2:19pm UTC](https://calculix.discourse.group/t/tabular-contact/1423 "2022-12-27T14:19:01Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ashinbrot](https://avatars.discourse-cdn.com/v4/letter/a/c77e96/32.png) [@ashinbrot](https://calculix.discourse.group/u/ashinbrot)\ **Post date:** [December 27, 2022, 2:19pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/1 "2022-12-27T14:19:01Z")
I’m having trouble with tabular contact–the solver does not see the contact. So I simplified my problem–I took a simple contact example problem (cubes.inp) and changed it to tabular contact. The original surface stiffness was 1e7, I changed this to (0.,0.) and (1e7,1.), which should be the same (or perhaps this is my problem, please advise). Using the original pressure loading didn’t converge, often seen in contact problems, so I changed the loading to a small displacement. The model behaves perfectly, it just ignores the contact condition. Input file below, I apologize if there is a way to attach a file, I didn’t see it. \*NODE, NSET=Nall 1,1.000000000000e+00,1.000000000000e+00,0.000000000000e+00 2,1.000000000000e+00,0.000000000000e+00,0.000000000000e+00 3,1.000000000000e+00,0.000000000000e+00,1.000000000000e+00 4,1.000000000000e+00,1.000000000000e+00,1.000000000000e+00 5,0.000000000000e+00,1.000000000000e+00,0.000000000000e+00 6,0.000000000000e+00,0.000000000000e+00,0.000000000000e+00 7,0.000000000000e+00,0.000000000000e+00,1.000000000000e+00 8,0.000000000000e+00,1.000000000000e+00,1.000000000000e+00 9,1.000000000000e+00,5.000000000000e-01,0.000000000000e+00 10,1.000000000000e+00,0.000000000000e+00,5.000000000000e-01 11,1.000000000000e+00,5.000000000000e-01,1.000000000000e+00 12,1.000000000000e+00,1.000000000000e+00,5.000000000000e-01 13,5.000000000000e-01,1.000000000000e+00,0.000000000000e+00 14,5.000000000000e-01,0.000000000000e+00,0.000000000000e+00 15,5.000000000000e-01,0.000000000000e+00,1.000000000000e+00 16,5.000000000000e-01,1.000000000000e+00,1.000000000000e+00 17,0.000000000000e+00,5.000000000000e-01,0.000000000000e+00 18,0.000000000000e+00,0.000000000000e+00,5.000000000000e-01 19,0.000000000000e+00,5.000000000000e-01,1.000000000000e+00 20,0.000000000000e+00,1.000000000000e+00,5.000000000000e-01 21,7.500000000000e-01,7.500000000000e-01,1.000000000000e+00 22,7.500000000000e-01,2.500000000000e-01,1.000000000000e+00 23,7.500000000000e-01,2.500000000000e-01,1.500000000000e+00 24,7.500000000000e-01,7.500000000000e-01,1.500000000000e+00 25,2.500000000000e-01,7.500000000000e-01,1.000000000000e+00 26,2.500000000000e-01,2.500000000000e-01,1.000000000000e+00 27,2.500000000000e-01,2.500000000000e-01,1.500000000000e+00 28,2.500000000000e-01,7.500000000000e-01,1.500000000000e+00 29,7.500000000000e-01,5.000000000000e-01,1.000000000000e+00 30,7.500000000000e-01,2.500000000000e-01,1.250000000000e+00 31,7.500000000000e-01,5.000000000000e-01,1.500000000000e+00 32,7.500000000000e-01,7.500000000000e-01,1.250000000000e+00 33,5.000000000000e-01,7.500000000000e-01,1.000000000000e+00 34,5.000000000000e-01,2.500000000000e-01,1.000000000000e+00 35,5.000000000000e-01,2.500000000000e-01,1.500000000000e+00 36,5.000000000000e-01,7.500000000000e-01,1.500000000000e+00 37,2.500000000000e-01,5.000000000000e-01,1.000000000000e+00 38,2.500000000000e-01,2.500000000000e-01,1.250000000000e+00 39,2.500000000000e-01,5.000000000000e-01,1.500000000000e+00 40,2.500000000000e-01,7.500000000000e-01,1.250000000000e+00 \*ELEMENT, TYPE=C3D20, ELSET=Eall 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 17, 18, 19, 20, 13, 14, 15, 16 2, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 37, 38, 39, 40, 33, 34, 35, 36 \*NSET,NSET=Nfix 1, 2, 5, 6, 9, 13, 14, 17, \*BOUNDARY Nfix,1,3 \*NSET,NSET=Nfix2 23, 24, 27, 28, 31, 35, 36, 39, \*BOUNDARY Nfix2,1,2 \*SURFACE,NAME=Sslav 2, S3 \*SURFACE,NAME=Smast 1, S5 \*CONTACT PAIR,INTERACTION=SI1,TYPE=SURFACE TO SURFACE Sslav,Smast \*SURFACE INTERACTION,NAME=SI1 \*SURFACE BEHAVIOR,PRESSURE-OVERCLOSURE=TABULAR 0.,0. 1e7,1. \*FRICTION 0.2,1.E5 \*MATERIAL,NAME=EL \*ELASTIC 210000.,.0 \*SOLID SECTION,ELSET=Eall,MATERIAL=EL \*NSET,NSET=Nload 23, 24, 27, 28, 31, 35, 36, 39, \*STEP,NLGEOM \*STATIC \*\*\*DLOAD \*\*2, P5, 100.000000 \*\*2, P1, 10.000000 \*BOUNDARY NLOAD,3,3,-.1 \*NODE FILE U, S \*EL FILE S \*CONTACT FILE CDISP \*EL FILE U,S \*END STEP ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [December 27, 2022, 3:13pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/2 "2022-12-27T15:13:22Z")
> [@ashinbrot](#): > > \*SURFACE BEHAVIOR,PRESSURE-OVERCLOSURE=TABULAR > 0.,0. > 1e7,1. This definition means that there’s zero contact pressure for zero overclosure (perfect contact) and then the pressure jumps to 1e7 for overclosure (penetration) of 1. ---
**Author:** ![ashinbrot](https://avatars.discourse-cdn.com/v4/letter/a/c77e96/32.png) [@ashinbrot](https://calculix.discourse.group/u/ashinbrot)\ **Post date:** [December 27, 2022, 4:18pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/3 "2022-12-27T16:18:57Z")
Yes, for linear contact (cubes.inp) the slope was 1e7, and I believe linear assumes zero pressure at zero over-closure. So my idea was to mimic that with a table, since the linear model did converge and see contact. ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [December 27, 2022, 4:27pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/4 "2022-12-27T16:27:51Z")
> [@ashinbrot](#): > > I believe linear assumes zero pressure at zero over-closure That’s right: > The linear pressure-overclosure behavior (Figure 130) simulates a linear relationship between the pressure and the overclosure. At zero overclosure the pressure is zero as well. ![linear](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/a/a23956efaf1c27ebed51a3af78b143ed202c8cc3.jpeg) But you have to keep in mind that for tabular pressure-overclosure you specify pressure instead of slope. ---
**Author:** ![Disla](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/disla/32/3548_2.png) [@Disla](https://calculix.discourse.group/u/Disla)\ **Post date:** [December 27, 2022, 5:57pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/5 "2022-12-27T17:57:45Z")
It works for me but just for node-to-face contact not surface-to surface. Curiously , in the manual it is shown under the node-to-face group when talking about \*GAP CONDUCTANCE. That’s what made me try it and worked. \*Surface interaction, Name=Surface\_interaction-1 \*Surface behavior, Pressure-overclosure=Tabular ![imagen](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/0/0068686b786254473f9d0aa27fb06ef63271562d.png) \*Friction 0.3, 1000000 \*\* \*\* Contact pairs +++++++++++++++++++++++++++++++++++++++++++ \*\* \*Contact pair, Interaction=Surface\_interaction-1, **Type=Node to surface** , Small sliding Sslav, Smast > **[Contact Tabular.pmx](https://wetransfer.com/downloads/688006b01e0d1e097b5450aea5031d8d20221227180414/168b96)** > > 1 file sent via WeTransfer, the simplest way to send your files around the world ---
**Author:** ![ashinbrot](https://avatars.discourse-cdn.com/v4/letter/a/c77e96/32.png) [@ashinbrot](https://calculix.discourse.group/u/ashinbrot)\ **Post date:** [December 27, 2022, 6:40pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/6 "2022-12-27T18:40:11Z")
Yes. For Linear you provide the slope, for tabular you provide pressure / overclosure pairs (theoretically, but I can’t make it work). ---
**Author:** ![ashinbrot](https://avatars.discourse-cdn.com/v4/letter/a/c77e96/32.png) [@ashinbrot](https://calculix.discourse.group/u/ashinbrot)\ **Post date:** [December 27, 2022, 6:41pm UTC](https://calculix.discourse.group/t/tabular-contact/1423/7 "2022-12-27T18:41:09Z")
Ah, thank you. I thought I’d tried everything, but node-to-surface I didn’t. Thank you again.