Why am I getting members failing in compression in tension-only members?


I have a model of a pipebridge that when analysed on my machine takes 2 hours to run, however, when it has finished it is giving me results showing some cross bracing members failing in BS5950-1:2000 compression checks, even though they have been assigned as Tension-Only. It is running the latest STAAD software (STAAD Pro CONNECT Edition v 22 Update 5) with the Advanced licence.

On my colleagues machine that is running an earlier update (STAAD Pro CONNECT Edition Update 3) with the Advanced licence the exact same model (.std file) it takes 6 hours to run but is not getting these compression failures.  It seems as if my software is ignoring the Tension-Only command, is there a fault in my software?

Some screenshots of a the results of a typical cross bracing member from my analysis are provided in the doc file attached and the .std file is also attached.

I note that in a similar thread from about December 2020 a user seems to be having the exact same issue when using the New Zealand code with the reply suggesting that it is a software error, but it does not seem that thread was ever resolved.  The last reply by someone named Sye stated "Bug #515693 has now been filed based on the Help Ticket 511058 and this issue will be fixed by our development team."

What would you suggest can be done to resolve the issue so that my machine gives me the correct results?


Richard Micklewright

 DOCXSTAAD Chikara A2 with New pipe plusXminZ PQ1_PQ3_PQ6 24 feb 21.std