AISC Section Dimensions Help 2

[desaut]

I am building a free online resource for engineers.
First, I want to add all steel section properties and dimensions to the database. I've found an Excel spreadsheet AISC Shapes Database v16.0.
The section properties are fine, but I am struggling to understand how to build section shapes for CAD files for engineers to download.
Here is the list of assumptions I wanted to clarify:
1. For all I-beams the fillet radius between web and flange is k minus tf. Is this correct?
2. S-Shapes. What is the flange corner radius? I've found some references of it being either half of the web to flange fillet radius or 0.6 of the web thickness.
3. C and MC. What is the flange corner radius?
4. MC. What is the slope of the flange? Found 3 degrees mentioned in some forums, but no official confirmation.

The current tool has all the data from the AISC spreadsheet uploaded and available here https://spectacalc.com/listing/33/53.
Drawings and Figures are uploaded for:
- W-Shapes
- M-Shapes
- S-Shapes
- HP-Shapes
- C-Shapes

 

[jhnblgr]

North American Steel Sections|FREE CAD Blocks

Full Range of Shapes from AISC 14th Edition Shapes Database - All AutoCAD 2000 Format. Simply select, download & insert into your drawing - FREE!

www.cad-steel.com

 

[phamENG]

Much appreciated, but it's been done. jhnblgr posted one such resource. AutoCAD ships with dynamic steel shape blocks with editable property tables - they don't have them all, but they are easily updated (unless you have LT). Revit ships with all the steel shape families preloaded.

If a dimension isn't listed, then it likely isn't 'standardized.' Though none of those dimensions are really standards, per se....AISC uses measurements from as rolled shapes to build those tables. That's while the table updates with every manual. It's usually hard to find changes, but there's usually something in there. It'll be minor, but might have an ever so slight impact on detailing.

 

[JStephen]

As I understand it-
The corner radiuses, etc, vary slightly with manufacturer.
Section properties (I, S, Z) are based on minimum radius.
Tabulated radius is maximum radius, which is required for detailing, bolt clearance. So working backwards from tabulated radius doesn't necessarily give you the tabulated section properties.
Some of the section properties are not well defined, which doesn't help.

 

[desaut]

Much appreciated, but it's been done. jhnblgr posted one such resource. AutoCAD ships with dynamic steel shape blocks with editable property tables - they don't have them all, but they are easily updated (unless you have LT). Revit ships with all the steel shape families preloaded.

If a dimension isn't listed, then it likely isn't 'standardized.' Though none of those dimensions are really standards, per se....AISC uses measurements from as rolled shapes to build those tables. That's while the table updates with every manual. It's usually hard to find changes, but there's usually something in there. It'll be minor, but might have an ever so slight impact on detailing.

Thank you phamENG,
I didn't want to reference AutoCAD, because I've found this thread with wrong slope values in MC shapes
https://forums.autodesk.com/t5/advance-steel-forum/b-report-as2022-mc-shapes-in-advance-steel-please-fix-the-flange/td-p/10636874
I don't believe anyone in Autodesk understands steel sections better than engineers on eng-tips.com

 

[desaut]

As I understand it-
The corner radiuses, etc, vary slightly with manufacturer.
Section properties (I, S, Z) are based on minimum radius.
Tabulated radius is maximum radius, which is required for detailing, bolt clearance. So working backwards from tabulated radius doesn't necessarily give you the tabulated section properties.
Some of the section properties are not well defined, which doesn't help.

thank you. Looks like AISC shapes are not standardized anywhere. So, my guesses about the radii are as good as others.

 

[Eng16080]

Nice work! I created a similar tool as an AutoCAD add-in which I use all the time to quickly draw sections.

1. For all I-beams the fillet radius between web and flange is k minus tf. Is this correct?
As mentioned above, I think that's the maximum radius you would expect the shape to have. Those are the dimensions I use to draw I-shapes.

2. S-Shapes. What is the flange corner radius? I've found some references of it being either half of the web to flange fillet radius or 0.6 of the web thickness.
I draw it with the curve starting at the bottom. I don't think that's entirely accurate but is good enough for my purposes. I have a PDF of the Carnegie Steel Pocket Companion from the 1920s which shows actual dimensions for S shapes. You may be able to find some useful information there. Of course, this assumes the shapes haven't changed over the years.


3. C and MC. What is the flange corner radius?
Same answer as for S-Shapes.

4. MC. What is the slope of the flange? Found 3 degrees mentioned in some forums, but no official confirmation.
According to the steel manual, p.1-4, "MC-shapes (also known as miscellaneous channels), which have a slope other than 16 2/3% (2 on 12) on the inner flange surfaces." I draw these with a slope of 2 on 12, despite this description, because I assume this is most likely to be accurate given the (unknown) variance.

AutoCAD ships with dynamic steel shape blocks with editable property tables

Most of the shapes are missing from the dynamic block making it rather useless (in my opinion). Besides that, it doesn't draw the I-beam web/flange radius correctly, as mentioned above, which could result in a detailing problem, like if you were to place a bolt too close to the radius, as such:


Besides that, for S sections, it doesn't draw the 2:12 inner flange slope correctly.

I was initially excited when I first found this dynamic block, but ultimately it lead to me creating my own tool. At the time, I couldn't find any suitable free tools online.

 

[desaut]

Nice work! I created a similar tool as an AutoCAD add-in which I use all the time to quickly draw sections.

1. For all I-beams the fillet radius between web and flange is k minus tf. Is this correct?
As mentioned above, I think that's the maximum radius you would expect the shape to have. Those are the dimensions I use to draw I-shapes.

2. S-Shapes. What is the flange corner radius? I've found some references of it being either half of the web to flange fillet radius or 0.6 of the web thickness.
I draw it with the curve starting at the bottom. I don't think that's entirely accurate but is good enough for my purposes. I have a PDF of the Carnegie Steel Pocket Companion from the 1920s which shows actual dimensions for S shapes. You may be able to find some useful information there. Of course, this assumes the shapes haven't changed over the years.
View attachment 3545

3. C and MC. What is the flange corner radius?
Same answer as for S-Shapes.

4. MC. What is the slope of the flange? Found 3 degrees mentioned in some forums, but no official confirmation.
According to the steel manual, p.1-4, "MC-shapes (also known as miscellaneous channels), which have a slope other than 16 2/3% (2 on 12) on the inner flange surfaces." I draw these with a slope of 2 on 12, despite this description, because I assume this is most likely to be accurate given the (unknown) variance.


Most of the shapes are missing from the dynamic block making it rather useless (in my opinion). Besides that, it doesn't draw the I-beam web/flange radius correctly, as mentioned above, which could result in a detailing problem, like if you were to place a bolt too close to the radius, as such:
View attachment 3549

Besides that, for S sections, it doesn't draw the 2:12 inner flange slope correctly.

I was initially excited when I first found this dynamic block, but ultimately it lead to me creating my own tool. At the time, I couldn't find any suitable free tools online.

Great. Thank you!

 

[phamENG]

Most of the shapes are missing from the dynamic block making it rather useless (in my opinion). Besides that, it doesn't draw the I-beam web/flange radius correctly, as mentioned above, which could result in a detailing problem, like if you were to place a bolt too close to the radius,

AutoCAD ships with dynamic steel shape blocks with editable property tables - they don't have them all, but they are easily updated (unless you have LT)

It's a pretty simple copy and paste from an excel sheet into the block editor to solve that problem.

 

[Eng16080]

It's a pretty simple copy and paste from an excel sheet into the block editor to solve that problem.

Having to copy and paste from a spreadsheet to edit the block for every shape that isn't included would defeat most of the benefit for me, especially considering there's no way to edit the block to make the fillet display correctly. I suppose you could explode the block and redraw the fillets, which might be a little faster than drawing it from scratch.

 

[RattlinBog]

I use Wisey's Steel Shapes LISP routine in AutoCAD. It's missing some new shapes but is still fairly comprehensive.

Link:
https://blog.draftsperson.net/wiseys-steel-shapes-lisp-program/