Composite section fails to converge in hogging

[Anonymous]

Hello,

I'm using SBD to calculate section capacities of a composite bridge. I have defined the section as attached.
Next, I define a dummy load case and go to General stress/strain. The sagging capacity looks fine, similar to my hand calculations but SBD fails to converge in hogging moment.
I've tried to change the iteration parameters, define dummy materials and even defining the reinforcement as equivalent rectangles ignoring the concrete and nothing seems to work.

Is there any way to work around this?

Many thanks,

Kevin

[Philip.Lee]

Hi Kevin

Please can you zip up your data file and attach it to the forum so we can run the file ourselves.

[Anonymous]

Hi Philip,

Thanks for the prompt reply. Please find attached the file.

Regards,
Kevin

[Philip.Lee]

I've taken a look at the file and have been having similar issues getting your section to converge.  I was able to get a converged solution in ASBD 2018 using the new interaction surface feature. This uses a different convergence system which is why I was able to get it to converge. Are you able to upgrade to that version and try that out?