Hi everyone. It is my pleasure to welcome you to this Interactive Learn Session to discuss about your queries related to Direct Analysis as per AISC 360 specifications and how to do it in STAAD.pro. This would be a great opportunity for all to share ideas and knowledge about this new analysis type. So let us get started …
Did you check out the wiki articles on Direct Analysis in the Bentley Communities forum ? If not, here is where you can find these communities.bentley.com/.../19522.direct-analysis
During the SIG session this morning someone was asking about the Tau-b reporting. Just wanted to mention that information on Tau-b are printed as part of the analysis output file. If such messages are not required to be printed, one can turn those off by using the following SET command as part of the command file.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 16-Nov-08
END JOB INFORMATION
INPUT WIDTH 79
SET NOPRINT DIRECT
UNIT FEET KIP
JOINT COORDINATES
...
During the SIG session this morning, some of the users wanted to know more about the 18 warnings obtained during the analysis. I am checking the model now and these were being caused by the fact that there were zero stiffness at certain locations in the model for example at the intersection of the X braces. Since the braces were specified as TRUSS members, at the intersection there was no ability to carry an out of plane force. These zero stiffness were causing high displacements at the nodes which were eventually causing the direct analysis to diverge leading to additional warnings. Working on the model right now. Will upload it shortly ...