AISC Design Examples - Some Questions

[Pororo]

1. For Ex.II.B-2 - Welded Flange plated FR Moment Connection (Photo below)
--> Why is the length, L, for the computation of flange plate compressive strength equal to 1.75?

2. For Ex. II.C-1 - Truss Support Connection
--> Why is the horizontal force passing through WT8x38.5 NOT considered in getting the tension forces in the bolt?
--> In computing the weld length at the top, how come the deduction in weld length at the horizontal potion (encircled
with red) is 1/8 in? Isn't the hold back supposed to be at least the weld size based on AWS D1.1?

THANKS!

 

[Celt83]

For 1: it is 1.75" because there is a 1" offset + 1/4" under-run(tolerance)+ 1/2" weld start location so the total unbraced length of the plate as a compression member is 1.75".

Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

 

[Ron247]

In question 2: The force in the WT is compressive with respect to the bolts I think. So other than any eccentricity causing a slight moment, it would have no effect on the bolts. Bolts are capable of tension and shear only I think. Also, before the force gets to the bolts, it is re-directed by the tension angle since the dog-eared plate is connected to the WT and not the Column.

What publication did you get these examples from?

 

[JoelTXCive]

They are from the AISC Design Examples.... (free!)

These are the design examples for the newest 15th edition

https://www.aisc.org/globalassets/aisc/manual/v15.0-design-examples/aisc-design-examples-v15.0.pdf

 

[Ron247]

Thanks a million, Joel.