Civil Engineering Reference
In-Depth Information
Center of gusset plate
i
h
b
2
b
3
_
w
e
w
e
l
c
d
b
1
30°
b
4
g
g
d
e
f
f
P
s
b
V
l
w
h
l
w
d
i
w
ne
= w
e
- n
b
d
bh
t
p
d
bh
= bolt hole dia.
n
b
= no. bolts on line d-d
(3 in this Figure)
e
c
Gusset plate with thickness,
t
p
,
is component of bottom chord
splice
FIGURE 9.18
Typical truss gusset plate connection.
reviewed for combined stresses (see Chapter 8) from the following:
• Shear field,
V
, on the gross section of the gusset plate from resultant
horizontal and vertical forces in the members
• Axial tension or compression,
P
, on the gross section of the gusset plate
from resultant horizontal and vertical forces in the members
• Bending moment, for example
M
=±
±
V(d
e
)
P(e
c
)
at section g-g in
Figure 9.18.
Critical sections such as f-f and i-i in Figure 9.18 should also be reviewed for
combined stresses from the following:
• Shear fracture,
V
, on the net section of the gusset plate from resultant
horizontal forces in the members
• Axial tension or compression,
P
, on the net section of the gusset plate from
resultant vertical forces in the members
• Bending moment
For gusset plates in very complex connections or in long span trusses, the detailed
analysis of gusset plate connections by finite element analysis is often warranted.
In addition, free edge lengths on the gusset plate should be minimized to pre
clude
localizedbucklingeffects.Manyengineersrestrict
b
i
/t
p
ratiostolessthan2.06
E/F
y
(
i
1, 2, 3, and 4 in Figure 9.18). Edge stiffening angles sho
ul
d be used when the
free edge distance is large and be proportioned such that
b
i
/
√
w <
120.
Example 9.4 outlines the design of an axially loaded bolted connection using block
shear and Whitmore stress block analyses.
=
