All bolted single-angle connection 2

[wag2483]

Requesting some direction on identifying the Lc dimension for Bearing strength at bolt holes for in plane eccentricity. Using the 13th edition of AISC. Spec J10(a) notes independent of the direction of loading however Lc is defined just below as clear distance in the direction of force. Understood that the coefficient table is available but prefer to hand calculate as well. Thank you

 

[canwesteng]

You should be far enough away from an edge that this won't govern if you are using standard details. The actual distance to an edge can't be determined without knowing the geometry of the clip in any case, but it is always conservative to take the smallest edge distance.

 

[wag2483]

Thanks, that makes sense. Looks like shear does barely govern over both bearing edge and spacing in this case. AISC Design example version 14 does have an all-bolted single angle example problem, where oddly enough bearing governs. Naturally they threw themselves a softball and used a C value from table 7-8.

 

[271828]

The same example is done a little differently in the 16th edition. Might consider checking it out.

https://www.aisc.org/publications/s...ion-manual/manual-companion-for-16th-edition/

 

[canwesteng]

I think there could be cases where bearing governs, given that the web of the supporting or connecting member can be fairly thin if loads are light enough that you are using a single angle. I don't think that the edge tearout (where you use the l.c) can govern for any of those cases, since when edge distance is more than half the bolt diameter, bearing always governs.

 

[wag2483]

The example goes on to check flexure for one of the angles legs. The calculation uses Zx from the property table, however the Zx neutral axis is about one leg vertical and another horizontal. The connection is positioned with both legs vertical. Why is Zx not calculated like a vertical plate for a single vertical angle leg?

 

[271828]

I'm not sure what you're looking at. I'm looking at the 16th ed. Page IIA-271 and 272.

The PNA is horizontal and perpendicular to the supporting girder. Please see below and let me know if that makes sense.

 

[lexpatrie]

I didn't know the 16th edition examples are available for free download. thanks 271828, I updated the various FAQs in the AISC forum, moved the 15th edition design examples down to Technical Background and added the link for the 16th edition (2023) to the Design Resources.