There's "how to win friends and influence people" and then there's its antithesis: "how to lose friends and alienate people."
Unreal. I thought this was joke/satire post at first, but it seems you're serious. Please do some deep introspection if you truly believe this is an acceptable way to...
Bones, be sure to read through the RisaSection Help document. Especially important to understand how it takes vertical slices through the section to determine flange dimensions. You can overwrite flange and web dimensions if it's giving you an average due to unequal flanges.
Also, before you...
Do you have nearby girders and enough room to frame the opening with new beams from below? Then attach new decking, place reinforcement, and pour concrete. This would just end up being a non-composite, simple span of slab, if you can live with that for your load demands or other requirements.
The only reason I caught the hp mistake in Risa was because I was using it to check the accuracy of an Excel design aid I was developing for my M.S. project (see thread in the structural forum). I was checking 12 different cross-sections, and 2 of them had the hp issue. Those 2 were a (1) W12x40...
Sorry, my question was about what folks thought about me also sharing my project report pdf on eng-tips. Would that be too much or against some rules? The report is 100+ pages and describes the development, capabilities, limitations, and accuracy verification for the design aid, as well as goes...
TLDR: Risa-3D calculates hp as a negative number anytime the PNA is within the compression flange of a singly symmetric beam cross-section. This causes a noncompact web and messes up flexure Section F4 equations, reducing bending strength. AISC 360-16 (or -22).
Risa support confirmed that the...
Good idea--I'll see what I can do.
I'm not sure what you mean?
Would it be strange or against forum rules to post and attach my project report here in about a month when I'm done working on the design aid? I would probably remove the cover page.
Only reason I thought it would be helpful is...
Quite the humblebrag of you to say you can break foundations with some punches. : o)
Going out on a limb without any evidence, is there a chance your photo is showing an outer layer of painted stucco? The texture makes me think of a cosmetic surface, not the foundation itself, but I could be...
Up to you and what you're getting for analysis results. Setting the square root term to 1 can be conservative, especially with larger J values. I can't comment on your particular design as I don't know any of the details or key variables like Lp, Lr, rts, etc. I'm also not sure which code you're...
I'm not familiar with the BS code. The AISC steel construction manual describes the use of web stiffeners to provide stability for beams continuous over columns in Part 2 - "Beams and Girders Framing Continuously over Columns." Fig. 2-2d in the 16th ed manual. It's commonly used.
You said...
AISC 360-16 F1 states, "For cantilevers where warping is prevented at the support and where the free end is unbraced, Cb = 1.0."
Load placed on an unbraced top flange will produce a tipping effect, but load suspended from an unbraced bottom flange (e.g. monorail) will have a stabilizing effect...
I'm debating whether I should add a part about considering pre-load (existing load at the time of reinforcing a steel member) to my design aid.
Bo Dowswell provides guidance and equations on how to determine if the reinforcement steel is "stabilizing" to the new built-up shape. Reinforcement is...
For field stitch welds, I'm typically more concerned with the pitch than the weld length. AISC 360 J3.5 gives requirements for max fastener spacing for painted/unpainted steel and steel subject to corrosion. Section E6 gives even more stringent connection spacing requirements for built-up...
Cpw629, Yes, that's the plan. Thanks for the offer, but I'll wait until I'm done in a few weeks to upload/publish it. I'd rather not have a draft floating around in the wild.
I already have a couple people checking it, and I also rebuilt the entire design aid in Mathcad to verify every...
I'll likely protect the formulas but without a password to prevent accidental modifications but to still allow folks to update the spreadsheet intentionally when newer editions of AISC 360 come out.
I think the only small concern I had was somehow taking on risk/liability if someone were to...
Over the last two years, I developed a steel beam-column design aid according to AISC 360-22 for my M.S. civil engineering non-thesis project. The design aid (built in Excel) can be used to analyze and design shapes with original, reduced/corroded, and reinforced/built-up section properties...
Have you considered working for an owner, sales, contractor, fabricator, etc. but still as structural engineer? Consulting can definitely be a grind. Maybe it would be refreshing to try structural from a different slice of the pie.
Would it be appropriate to design as a pin-connected member (AISC 360-16 sect. D5)? That provides some geometrical limitations on the tensile and shear rupture strength. Need to check bolt shear, bearing, and tearout, of course.
I am by no means an expert on this topic. I found one example in the SDI Diaphragm Design Manual 3rd Ed (attached). https://files.engineering.com/getfile.aspx?folder=1ef4c222-ec7c-4762-9b4e-431f8fb1a83b&file=SDI_diaphragm_design_manual_example.pdf
