Thanks for the response. I respectfully disagree that you would apply the wind pressure to all faces for Fig.29.5-3. If that were the case, then Fig.29.5-3 would always give larger overall wind force vs. Fig.29.5-2, and by a very significant margin (60-90% difference for e=0.05-0.30 as...
I have a number of questions regarding ASCE 7-10 wind loads.
1.
Say you have a trussed tower and want to use either Fig. 29.5-2 for lattice framework or 29.5-3 for trussed towers. The Cf factors come out to be very different. From studying the figures and footnotes I’m under the impression...
Good news everyone, I had posed my original question to AISC at the same time I posted here and they finally responded back. The information they sent was really helpful and hopefully it’s helpful to you as well.
The first thing they pointed me to was pg. 2-19 of the AISC Steel Construction...
Regarding stiffener plates on the beams over columns, what do you think about partial height stiffeners? Such as stiffeners that are roughly 3/4 the height of the beam, welded to the bottom flange and web. I imagine there’d be some fabrication cost savings in using partial height vs. full...
JAE, thanks for the input. When I thought of using inflection points, I was thinking of taking the distance from one inflection point to the other inflection point past the column, basically taking the entire length that the bottom flange is in compression for. That would be about twice as...
What if vertical stiffeners from flange to flange weren’t present, would you still consider the column-beam attachment to brace the rotation?
As a hypothetical, say the purlins from the original example are smaller wide flange beams that run over the top of the beam in question (so there’s no...
Thanks for the responses. Based on the AISC definition of Lb, how can you justify the column locations as bracing the bottom flange? I don’t see the column stopping lateral displacement of the bottom flange, nor bracing it against twist.
What’s the most appropriate way to analyze a continuous steel wide flange beam over steel columns for flexure?
Consider a simple example:
-100 ft. long continuous steel wide flange beam (if there are any splices in the beam consider them CJP, effectively making it continuous. This may be...
I'm hoping someone can help me with some confusion I have on welds. Let's say I have a butt joint between equal thickness plates and the welding process is SMAW. I want to avoid CJP and I'd like to weld from one side, so I'm considering one of 3 options between B-P1c, BC-P2, and BTC-P4, as...
I have a 2 part question about ASCE 7-10 Fig. 28.4-1. I've mostly used Ch. 27 for MWFRS wind, so I'm less familiar with Ch. 28.
First, why does load case 'A' not have side wall pressures?
Second, when you have a flat roof (zero degrees), you no longer have a definitive ridge, so which load...
