Iterations have failed to converge at result point of interest 1 in Post-tensioned Concrete Beam Analysis

[Anonymous]

Hi,

I am checking a post-tensioned concrete beam for different load cases. I am getting the following two errors one after the other when I analyse for Construction Sequence 1 and 2. I get these messages at every point of interest. Can you please help?

Regards,

Liaqat

[dave_geeves]

Hi Liaqat,

This error message indicates that the program cannot find a solution to the strain compatibility analysis.  For post-tensioned design beams this can occur if there is not enough (or indeed any) reinforcement in the tension zones of the beam.  I do not know what the details of your beam are, but if you have only specified post-tensioned tendons with no unstressed reinforcement than it is quite possible that in some areas and load cases  the tendons are in the compression part of the beam.  Try adding some nominal reinforcement in both top and bottom to see if this solves the problem.

If this does solve your problem then please mark this reply as a solution so that others can benefit.  If not, then please zip up your data file(s) and attach to a reply to this post so that I can investigate.  Thanks

Kind regards

Dave Geeves