Page 326 - Handbook of Structural Steel Connection Design and Details

Partially Restrained Connections

Partially Restrained Connections 311

Following the nomenclature in Fig. 4.18,

2s16d
2w T
p 5 5 5 4 in/bolt
n tb 8
1.3125
d th
5 a1 2 b 5 a1 2 b 5 0.672 in
p 4.00
Assuming the gage of the tension bolts (g ) as 8 in. in order to avoid clear-
tb
ance problems:

t st,eff 5 t st 1 2k 1 5 0.96 1 2s1.69d 5 4.33 in
1 1
b 5 Q Rsg t 2 t st,eff d 5 Q Rs8 2 4.33d 5 1.84 in
2 2
1
b 5 b 2 d b 5 1.84 2 0.63 5 1.21 in
2
1
a 5 1 d b # 1.25b 5 1.88 in , 1.25s1.60d 5 2.00, ok
2
1
a 5 a 1 d b 5 1.875 1 0.625 5 2.50 in
2
b ft 5 g tb 1 2a 5 8 1 2s1.88d 5 11.75 in

The flange width of the W 40 264 is 11.9 in. For fabricating ease, take
a 1.88 in and g 8.16 in (correspondingly, b 1.92 in, b 1.29 in, and
t
a 2.50 in).
15. The capacity of the tension bolts is computed as

2
t r nt 5 A b F nt 5 s0.75ds1.23 in ds113 ksid 5 104.3 kip/bolt
The required T-flange capacity in units of kips per tension bolts is

765.8 kip
F pr
T reqd 5 5 5 95.7 kip/bolt # r nt ok
n tb 8 bolts
16. Determine adequacy of the flange thickness. Three mechanisms can be pos-
tulated:
a. For a pure plastic mechanism in the tension flange, the required design
resistance per tension bolt is

s1 1 d
2
T 1 5 spds d F y dst ft d
4b
s1 1 0.672d
2
5 s4.00ds1.00ds50ds1.73d 5 193.9 kip/bolt
s4ds1.29d

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