Page 82 - Handbook of Structural Steel Connection Design and Details

Design of Connections for Axial, Moment, and Shear Forces

Design of Connections for Axial, Moment, and Shear Forces 67

Since 11.0/11.0 1.0 1.25, the weld size based on the average
force in the weld, f 1.25, therefore
ave
11.0 3 1.25
D 5 1.5 5 7.09
1.392s1 1 0.5 sin s58.2dd
1
A / fillet weld is indicated. The 1.25 is the ductility factor; see
2
Hewitt and Thornton (2004).
An alternate method for calculating the weld size required is to
use Table 8-38 of the AISC Manual of Steel Construction (2005),
special case k 0, P 349, and al 4205/349 12.05 in; thus
u
a 12.05/30 0.40 and c 2.00, and the required weld size is
349
D 5 5 5.8
2.0 3 30
3
A / fillet is indicated. This method does not give an indication of
8
peak and average stresses, but it will be safe to use the ductility
factor. Thus, the required weld size would be
D 5.8 1.25 7.25

Thus, by either method, a 1/2 fillet is indicated.
c. Checks on beam web:
(1) Web yield: Although there is no axial component, the couple M
B
4230 kips-in is statically equivalent to equal and opposite ver-
tical shears at a lever arm of one-half the gusset length or 15 in.
The shear is thus
4230
V s 5 5 282 kips
15
This shear is applied to the flange as a transverse load over
15 in of flange. It is convenient for analysis purposes to imag-
ine this load doubled and applied over the contact length N
30 in. The design web yielding strength is

R wy 5 1.0 3 50 3 0.47s30 1 2.5 31.27d 5 780 kips . 282 32
5 564 kips, ok

(2) Web crippling:
30 0.47 1.5
2
R wcp 5 0.75 3 0.8 3 0.47 c1 1 3a ba b d
24.1 0.77
29000 3 50 3 0.77
3 5 568 kips . 564 kips, ok
B 0.47

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.