Civil Engineering Reference
In-Depth Information
Example: Assume
V
=
1500 lb
F
nail
=
nail capacity
= 140
lb perfastenerinc
luding allowableincreases
n
= 2 webs both sides
y
= 7 282
.
in
QAy
f
=
=
1555 7 282
.(.)(.
)
=
60
in
3
fl
I
t
= 1493 54
.
in
4
totalmomentofinertia
2 140 1493 54
1500 60
(
)(
.
)
Nail spacing =
=
465
.
′′
oc
▲
. .
()
Panel Zone Shear Transfer Using Nails in Lieu of Gluing (Shear Plus Rotation)
(See Fig. 14.12)
∑∑
2
2
4
polarmomentofinertia,inoffnailpattern
JI I
=+=
dx
dy
x
y
2
2
Cxy
=+
distance to extremeouter nail, in
′ Z djustedallowableloadcapacityofa single nail perNDS,lb
MC
J
F
=
force, lb on extremeouter nail dueto
rotation
rot
The vertical and/or horizontal shear applied directly to the joint must also be com-
bined with the vertical and horizontal force component of the shear caused by rotation,
as shown at the left of the figure.
F
=
(
HF
+
)
2
++ resultantforce on extr
(
VF
)
2
emeouter nail
R
h
v
where
H
= horizontal force component of
F
rot
,
lb
V
= vertical force component of
F
rot
,
lb
F
h
= shear applied to nail from horizontal force applied to joint, lb
F
v
= shear applied to nail from vertical force applied to joint, lb
14.6
The Portal Frame Wall
Example 14.1: The Portal Frame with Gravity Loads
Portal frames based on nailed-only, tested assemblies using semirigid joints were covered
in Chap. 13. The method of analyzing those types of walls can be found in the reference.
8
The method outlined in that paper does not follow the methods described in this chapter
for glued moment-resisting framed walls with rigid joints. This example is presented so
that a comparison of the results can be made with other portal frame examples in this
book. The analysis of this frame is applicable to moment-resisting wood-frame walls
of all configurations (see Probs. 14.1 through 14.3). The frame in Fig. 14.16 has a wall
height of 10′-0″ and a width of 18′-6″. The left and right piers consist of two 2 × 6 outer
studs and three 2 × 6 inner studs. The header section consists of two 2 × 6 top plates
and three 2 × 8 built-up headers. Sheathing is applied on both sides of the wall. The face
Search WWH ::
Custom Search