Civil Engineering Reference
In-Depth Information
The shear on the right side of the left panel (near grid line 4) is equal to 704.2 lb and
is acting in the downward direction. The shear at grid line 3 is equal to
VVwx
3
=− =−
704 2
.
−
123 12 5
(
.)
= −
2241 6
. bactingupward
4
V
D
2241 6
10
.
v
==
3
=+
224 2
.plf unit shear
3
Shears at grid line 5 at the lower panel, summing to the left:
V
5
=−
4166 67
.
lbactingupward
VVwx
left
=− =
4166 67
.
−
77 15
(
)
=+
3011
lb acting down
ward
5
V
D
3011
50
left
v
=
=
=−
60 22
.
plfunitshear
left
The shear on the right side of the left panel at grid line 4 is equal to 3011 lb and is
acting in the upward direction, creating a negative unit shear in the sheathing.
V
D
3011
40
right
v
=
=
=−
75 3
.
plfunitshear
right
VV
=
−
wx
=
3011
−
77 10
()
=+
2241
lb acting downwa
rd at grid line3
3
right
V
D
2241 6
40
.
3
v
==
=−
56 04
.
lf unit shear
3
Summing the total shear from the upper and lower panels at grid line 3 as a check:
∑
=+
2241 6
.
−
2241 60
.
=
,which matchesbasic sheardiagram
∴
K
In the upper panels it can be seen that the unit shear goes from a positive 224.2 plf
at grid line 3 to a negative 83.33 plf at grid line 5. The shears transferred into the collec-
tor at the bottom of the upper panels should be applied to the figure for reference. The
shear diagram of the transferred shears is plotted below the panels. The area of the
positive shears acting on the collector is transferred into transfer diaphragm TD1 on
the left. The area of the negative shears acting on the collector is transferred into
transfer diaphragm TD3 on the right. The force that is acting to the left becomes
vL
1
2
224 21823
2
.( .
)
334
−
F
=
bh
=
=
=
2043
lb compr
ession
,
positive force
32
,.
A
2
This force is transferred into transfer diaphragm TD1. Observing the direction of
the shears transferred into the collector at grid line 5, A.2, the force applied to transfer
diaphragm TD3 is also in compression. This will be confirmed when the longitudinal
collector force diagrams are calculated. It is interesting to note that the force
F
= 0 in the
member at the bottom of the upper panel does not occur at the assumed location
(i.e., halfway between grid lines 3 and 5).
The force in the collector at the top of the bottom left panel between grid lines 3 and
3 + 10′ is
56 04
.
+
75 3
.
F
=
()
10
=
656 7
. bcompression
2
Search WWH ::
Custom Search