Learning Forum

[sr1993]

ELBOW290 is used for pipelines and SHELL181 is used for sleepers.

In which the seabed is in contact with submarine pipes using 170 and 175 and the seabed is in contact with sleepers using 170 and 176.

After applying the temperature, the transient analysis results show that the displacement in Y direction is as follows, and the unknown is marked in gray. I don't quite understand why this is the case, and whether my contact pair is wrong. I hope the teacher can give some suggestions.

Sleepers are in the z direction and pipes are in the x direction, and the pipes are carried on sleepers.

[John Doyle]

It is hard to say for sure without seeing the model input, but CONTA175 and 176 use nodal detection and the graphics (even in MAPDL) are limited.nA lot of results can be postprocessed via using APDL commands. If you look up CONTA175 in the MAPDL Elements Reference Manual, you will find a table of available output quantities. It is similar for CONTA176.nFor example, you can extract contact pressure and plot the pressure result in MAPDL GUI with the following commands:nETAB,cpress,smisc,1nPLETAB,cpressnYou can also print the same results with PRETAB command.n

[Mike Rife]

To add to what John said single node elements show up with that grey star symbol so we can tell where they are in the model. This would include element types like mass21, contact 175 (the node side of a node-to-surface pair), target 170 (which has a single node 'pilot node' and 'point' representation feature), etc. Miken

[sr1993]

Hi @sr1993 To add to what John said single node elements show up with that grey star symbol so we can tell where they are in the model. This would include element types like mass21, contact 175 (the node side of a node-to-surface pair), target 170 (which has a single node 'pilot node' and 'point' representation feature), etc. Mikehttps://forum.ansys.com/discussion/comment/108376#Comment_108376

First of all, thank you for taking the time to answer my questions. You mean that after I establish contact, these gray node marks will not affect my subsequent results, right?n

[sr1993]

It is hard to say for sure without seeing the model input, but CONTA175 and 176 use nodal detection and the graphics (even in MAPDL) are limited.A lot of results can be postprocessed via using APDL commands. If you look up CONTA175 in the MAPDL Elements Reference Manual, you will find a table of available output quantities. It is similar for CONTA176.https://us.v-cdn.net/6032193/uploads/JMA04FO9TPCU/image.pngFor example, you can extract contact pressure and plot the pressure result in MAPDL GUI with the following commands:ETAB,cpress,smisc,1PLETAB,cpressYou can also print the same results with PRETAB command.https://forum.ansys.com/discussion/comment/108347#Comment_108347

First of all, thank you for taking the time to help me look at it. Taking these gray signs doesn't affect my calculations, does it?n

[Mike Rife]

It depends on what element type the grey stars represent. If contact then yes, I'd expect that at some point contact would be established, if it is not in initial state of touching, and so affect the results...but that is your intent, correct?nMIken