AISC 360-22 Beam-Column Design Aid (Live for download!) 3

[RattlinBog]

https://sites.google.com/view/steel-design-aid

Above is the link to a Google Site I put together for the AISC 360-22 steel design aid I developed for my civil engineering M.S. grad project over the last couple years. You are welcome to download, use, and share freely! The download links simply pull from google drive. I also uploaded the design aid to steeltools.org, but it is still under review. I can post an update when it gets published.

There is an Excel file, which is the most comprehensive and full version; and there is a Mathcad Prime file, which is similar to the Excel file but with less features. For some reason, the Mathcad file takes a while to download, so just wait a couple minutes. I also provided a link to my project report for those interested in some background.

Reference this thread: https://www.eng-tips.com/threads/steel-design-aid-aisc-360-22-sharing-the-tool.523980/

I'm happy to answer questions on this thread or in the email I provided on the google site. I hope this is helpful to some folks!

 

[bones206]

This is really excellent work. I do a lot of renovation work and will be making great use of this tool. Thank you for sharing!

 

[RattlinBog]

Thank you--I'm happy to hear it! What started as a personal frustration with lacking resources for corroded and reinforced member design, turned into a bigger project that I wanted to share with others.

If you (or others) find errors or have suggestions for improvement/new features, feel free to send an email to the email address listed on the "User Guide" of the Excel file and at the bottom of the google site. I probably won't be messing with the design aid for a while as I just need a break from staring at it for 2 years, but I could start a backburner to do list if issues are found.

 

[EngDM]

I am excited to dig into this and adapt it to CSA requirements and Canadian load cases. If/when I get around to that, I will surely email you a copy. Scope is basically to address several of the design aid limitations. And adding HSS of course, although since they aren't LTB sensitive the equations are a little different, so hopefully thats easy to integrate.

Would be interesting to set up something that deals with the loade cases so you don't need to check each case manually.

 

[RattlinBog]

EngDM, sounds great!

Would be interesting to set up something that deals with the load cases so you don't need to check each case manually.

You may be thinking of the Analysis tab, which is only good for one simple-span beam, and yes, all loads are manually-entered.

However, Part 2 "Loads & Deflection Criteria" of the Design tab goes through the ASCE 7 load combinations based on user input for dead, live, roof live, snow, rain, and wind, but only for the following types of loads: full-length uniformly distributed load (entered as psf load, which is multiplied by tributary width in the background); concentrated load at midspan; and 2 equal, symmetrically-placed concentrated loads.

That's not going to cover every type and position of load, but it should cover many common scenarios.

 

[EngDM]

EngDM, sounds great!


You may be thinking of the Analysis tab, which is only good for one simple-span beam, and yes, all loads are manually-entered.

However, Part 2 "Loads & Deflection Criteria" of the Design tab goes through the ASCE 7 load combinations based on user input for dead, live, roof live, snow, rain, and wind, but only for the following types of loads: full-length uniformly distributed load (entered as psf load, which is multiplied by tributary width in the background); concentrated load at midspan; and 2 equal, symmetrically-placed concentrated loads.

That's not going to cover every type and position of load, but it should cover many common scenarios.

View attachment 1824

Correct me if I am wrong, but does the spreadsheet currently take the maximum of all load cases for shear/moment and run the combination equations with the maximums? If this is indeed how the spreadsheet is doing it, this may be overly conservative; you should be comparing the shear from the same combination with each moment. For instance, your max shear comes from wind, but max vertical comes from snow. The spreadsheet as it stands would use the highest wind factored, and the highest snow factored.

 

[RattlinBog]

You're probably right, but I might not be following what you're saying correctly. Are you talking about wind and snow on a column? The spreadsheet is definitely more "beam friendly." If you're designing a column, all the axial loads and weak axis bending would have to be done by hand and entered manually.

The spreadsheet just takes the shear and moment values for each type of load (dead, live, snow, etc.) and runs them through the ASCE 7 load combinations (both LRFD and ASD). It only does this for strong axis bending/shear and only for the three types of loading scenarios I listed in my last post.

 

[HDStructural]

First of all, very impressive. I like your format a lot and your project report is thorough and well written. I can see myself using this a lot and am currently 75% done with a reinforcement project. I plan to compare my final results to your spreadsheets to validate them for my own sake.

Looking in your Design tab, I have a few questions.

1. Do you think your design tab would still work for a section reinforced with angles as you have shown in your project report? I think it would still work well, only difference is that you might need to modify rows 696-700 since they are mainly used for compactness/slenderness checks and those would not be as straightforward when using angles to reinforce the beam.


For the next two question, I'm looking at the reinforced section design portion where you calculate the compactness ratios:
2. For the web flexure compactness, why don't you use the Distance Between Flanges, h, (row 730) in calculating h/tw? Sometimes it uses hc (row 732) which can be greater or less than h (row 730) depending on the reinforcement used. I would've thought h (row 730) should always be used here, or maybe hc (row 732) as long as it is not more than h (row 730).

3. For compression compactness checks, the flange compression check only considers the compression flange in bending. If the tension flange is more slender, the axial checks would not be done considering the slenderness of the thinner column flanges.
I know this was built for beams for the most part, and not columns. I can think of some work arounds for this, like checking two identical members where one has the reinforced flange input as the compression flange and the other as the tension flange. Whichever has the lower axial capacity would control.

 

[RattlinBog]

Thank you! I was reading your PEMB post the other day--looks like fun and a lot of work.

1. I believe it can, but I don't have sufficient evidence/use history to back that up. I'm assuming your shape looks like the below section. For rows 696-700 I would suggest entering those for the original WF only. The remaining section properties (Ix, Zx, J, Cw, Iyc, Afc, etc.) should capture the built-up WF + angles. You'll definitely want to manually-enter the optional inputs for Cw, Iyc, Afc, Iyt, and y_stiff to define that type of shape because your flange properties will be very different. If the reinforced flange alternates between compression and tension, you'll probably want to check it as two separate member in the spreadsheet.

This ties a bit into question 2, but for this type of shape, I think you'll want to enter a value for y_stiff to capture the smaller h because the angles stiffen the web (see "h (new)" below). y_stiff is a "pseudo" property I came up with to try to capture scenarios like this where a reinforcement shape is added that reduces the stiffened height of the web. If the reinforcement isn't full length, then tread lightly.



2. AISC requires the use of hc/tw to check the compactness of a web subject to flexure for singly symmetric I-shapes per Case 16 of Table B4.1b. See below. hc can be greater than h. hc increases when Sxt > Sxc and decreases when Sxc > Sxt. My spreadsheet checks that for singly symmetric shapes, which is triggered by an "if" statement when Sxc and Sxt are not equal. It's discussed very briefly in the AISC Commentary on Section F4. Also, if your PNA ends up in the compression flange, hp=0 and the web is compact.



3. My bad--I hid this one too well (not intentional). The slenderness check for the other (bottom) flange ended up in row 900 for [E7] Members with Slender Elements (Compression). A word of caution, the E7 check may not be perfectly dead on if your built-up shape starts to look funky and outside the bounds of a typical I-shape. However, if neither flange is slender for compression, then E7 won't control.

Hope that helps. I appreciate the questions--it helps me get a better feel for what works and what doesn't!

 

[HDStructural]

Thank you for your thorough explanation. I agree with your responses.

 

[RattlinBog]

Thank you for your thorough explanation. I agree with your responses.

If you think of it, do follow up on your PEMB project. I'd appreciate seeing what kind of differences you end up seeing for results between your current methods and the design aid (if you got that route). I haven't done much with WF + angle reinforcement in practice, so I don't have a great intuition for the design of that shape.


On a side note, what do folks think about me sharing the design aid / google site link on the Reddit structural engineering site? I don't really use Reddit at all. Only concern I have is that it makes it accessible to a large amount of people / general public, and I'm guessing many of the readers are laymen. Could it fall into the wrong hands?