Error with Max Combination Case

Hi All,

My CII model has a skewed piping, with a floating anchor in between (say at node 20).

In output, when I extract and compare "local element forces" with "Local Restraints" from a "MAX" combination case. I see that "Axial force" components at this node 20 do not match.

When I compare results of all cases individually(instead of max case), the results match.

Please let me know if there is a bug.. or am i missing something?

Thank you.

Hi,

This error occurs even for orthogonal restraints (e.g. along main coordinate axes), not only for skewed directions. There are cases when MAX combinations gives different maximum restraints' loads than those found by listing ALL operating cases and identifying maximum absolute values (e.g. Extended Restraint Summary Report).

When such error occurs? I am not aware about a clear template/typical case, but the errors occur in general for those restraints where friction factor is defined not only for vertical restraints, but also for horizontal guiding/stopping restraints.

There were in the past similar inquiries about this issue, Intergraph offered some explanations, but, honestly, till now I am not aware why such errors occur.
It is really frustrating MAX Load Case to be unable to offer reliable restraint summary results...

Regards,

Thanks a lot Sir.