Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: RISA-3D Steel WF Torsion

[Subject Prev][Subject Next][Thread Prev][Thread Next]

Try checking your frame model and make sure that all columns supporting the beams which are failing have the correct support condition (fixed or pinned). I had a similar problem when I forgot to put a support condition to column below a beam.




From: bill(--nospam--at) [mailto:bill(--nospam--at)]
Sent: Thursday, April 16, 2009 1:57 PM
To: seaint(--nospam--at)
Subject: RISA-3D Steel WF Torsion


I'm getting some anomalous results from a rather complicated steel frame run on RISA-3D. I'm doing RSA with this, and I have already noticed some peculiar results (at least for this "statics-based" puke).

When I look at the "Shear Check" plot on-screen, I'll see a lot of failures of wide-flange members (mostly beams), many with rather large "understrength factors" (if you will; I guess we used to say "overstress"), between 3.0 and 4.0.

But when I look at the specifics of a given member, I don't see any large shears at all. I'm inclined to think it might be a torsion problem showing up, but even the torsion doesn't seem that great (although it is present).

Any thoughts?