Page 175 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

160 Chapter Two

Using an elliptical interaction equation, which is analogous to the von
Mises (distortion energy) yield criterion,
V 2 T 2
a b 1 a b # 1
R bsv R bst
where V is the factored shear and T the factored tension. Then
33 2 39 2
a b 1 a b 5 0.34 , 1 ok
75.4 101
This interaction approach is always less conservative than the
2
approach using the resultant R 2V 1 T 2 as a shear because
R > R for the geometries of the usual bolt positioning in
bst bsv
double-angle connections with two or more bolts in a single vertical
column. The resultant approach, being much simpler as well as con-
servative, is the method most commonly used.
5
1
Connection angles. Figure 2.57 shows angles 5 3 / / , but assume
2 8
for the moment that 1/4 angles are to be checked. The shop legs are
checked for the limit states of bearing, gross shear and gross tension,
and net shear and net tension. Net shear rupture and net tension rup-
ture will control over block shear rupture with the usual connection
1
1
geometries, that is, 1 / edge and 1 / end distances. Since the sum of the
4 4
clip angle thicknesses 0.24 0.25 0.5 > 0.355, the beam web and
not the shop legs of the clip angles will control.
Prying action. The AISC LRFD Manual has a table to aid in the selec-
tion of a clip angle thickness.
The preliminary selection table, Table 15.1, indicates that a 5/8 angle
1
will be necessary. Trying Ls 5 3 / 5/8, and following the procedure
2
of the AISC Manual,
6.5 2 0.355 2 2 3 0.625
b 5 5 2.45
2
10.355 2 6.5
a 5 5 1.93s, 1.25 3 2.45 5 3.06 okd
2
0.75
b 2.45 2.08
2
0.75
a 1.93 2.31
2
2.08
0.90
2.31
8.5
p 5 2.83
3
1 0.8125/2.83 0.71

Downloaded from Digital Engineering Library @ McGraw-Hill (www.accessengineeringlibrary.com)
Copyright © 2009 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.