Civil Engineering Reference
In-Depth Information
The truss table system for deck forming. (Courtesy of Symons Corporation.)
Equating and solving for
,
2
120
w
f
S
f
S
w
10.95
Shear
In the same fashion, an expression can be written for the maximum permissible span
from the standpoint of horizontal shear. In the expression to follow,
H
is the allowable
shearing stress in pounds per square inch, while
V
is the maximum external shear ap-
plied to the member at a distance
h
from the support previously assumed to equal
0.6
w
[
(2
h
/12)].
(3)(0.6
w
)[
(2
h
/12)]
3
V
H
2
A
2
bh
used in the preceding expression was given in feet; therefore, when
the expression is solved for
The value of
, it must be multiplied by 12 to give an answer in inches to
coincide with the units of the moment and deflection expressions.
Hbh
0.9
w
2
h
12
12
