Hello everyone,
I tried to model a butt joint (bolt connection) in RFEM6. Unfortunately, I receive error message No. 56 (Incorrect topology of the surface contact) and do not know exactly where the error is. For modeling the bolt connection, I watched the corresponding videos on Dlubal's YouTube channel and followed the steps.
The RFEM file of the modeling is attached.
I look forward to your help.
Best regards
Kamaljit Singh Tatla
Hi Ka.Si.Ta,
Some surface contacts seem to be topologically incorrect. 
Please therefore carefully check your assignment of surfaces.
For example:
Surface contact 21 is supposed to connect surfaces 205 and 160
However, these two surfaces have no geometric connection
This suggests that there is probably an incorrect assignment here:
Best regards
Stefan Hoffmann
Thank you for your help, Stefan. The problem was that I had shifted a model area by 1 meter, which caused the surface contact to be lost. I have adjusted the surface contacts accordingly.
I ran the calculation and this time, for load case 3 at FE node no. 3939, I receive error message 10134 (The stiffness matrix is singular/Structure is unstable/FE mesh node no. 3939, in direction Z, increment 5). I performed a model check, which did not show any errors.
Can you help me further?
The modeling file is attached.
Thank you in advance.
Best regards
Kamaljit Singh Tatla
Hi Ka.Si.Ta,
Hello
For this message, you can find general notes in our FAQ:
https://www.dlubal.com/de/support-und-schulungen/support/faq/005345
Specifically for your caseIn your project, the load case cannot occur alone.
The simplest solution is therefore:
Calculate only the load combinations
Deactivate the individual load cases from the calculation
Best regards
Stefan Hoffmann