Hello,
I have a problem with my calculation.
I have applied a surface traction on the top of the fixture and I am trying to check the forces in the bolts.
I have created the Contact output, but when I go to the results > Total surface force, then there are practically no forces at all.
Could you please help me?
Thanks for the help.
Baseplate_connection.pmx (6.7 MB)
Request and check contact field outputs such as CPRESS and COPEN. You will see that contact acts in very small regions here and may have to be redefined (along with the mesh refinement). Surfaces used for contact pair definitions should be limited to the necessary areas (those that are touching and that may touch during the analysis), in your case they are way too large causing potential overconstraints.
i frequently simplified the model, concrete block idealized as compression only support, steel anchorage by two node spring elements. So a reaction force can be directly requested from its ground node.
Hi,
I was trying to find the solution in any way, that’s why I also tried to use all of the baseplate surfaces and all of the bolts surfaces. It didn’t work and I forgot to turn back to the only surfaces that are touching eachother before sending it here, sorry.
The problem is, that even with that change it doesn’t work. I was looking through the forum to find similar problems and I found one (Reaction forces - #5 by Gunnar) but it didn’t work out for me. The forces still don’t appear as they should and I don’t know why.
The updated file: Baseplate_connection.pmx (6.6 MB)
Thank you for trying to help me.
I think I know how to use the compression only support, but I lost it on the two node spring elements. How should I use it? Do I need to create two spring elements, one above eachother, in one hole? Could you explain it more? Its intresting.
Thank you
Check this thread too: Best way to find force in bolted connection
You could tie/merge the bolts for now and use *SECTION PRINT to get the forces.
Regarding springs, only the ones between a node and ground are available for now - other types (between two nodes) require keyword edits: Spring between two nodes
use surface coupling to connect with spring end nodes, there’s CalculiX keyword editor when features have not yet available.
also, representation of bolt anchorage by spring is nonlinear since it is limited to a tension only element.
Before meshing the compound, you need to select “Split compound mesh > Yes” to create unconnected parts (in your example, they are merged, so no forces are transferred through the contacts). You can simple check it by activating “explode view” in the FE Model window.
Thank you all for the answers!
It helped a lot.