- Ascertain whether the assumed size of the cover plates
satisfies the AISC Specification
Using the appropriate AISC Manual section, we find 7.56/0.375 = 20.2 < 32, which is ac-
ceptable;^1 X 2 (IO- 7.56)70.375 = 3.25 < 16, which is acceptable. - Test the adequacy of the trial section
Calculate the section modulus of the trial section. Referring to Fig. 40, we see /= 984 +
2(3.75)(9.31)^2 - 1634 in^4 (68,012.1 cm^4 ); S = IIc= 1634/9.5 = 172.0 in^3 (2819.08 cm^3 ).
The reinforced section is therefore satisfactory. - Locate the points at which the cover plates are not needed
To locate the points at which the cover plates may theoretically be dispensed with, calcu-
late the moment capacity of the wide-flange shape alone. Thus, M=JS = 24(107.8)712 =
215.6 ft-kips (292.3 kN-m). - Locate the points at which the computed moment occurs
These points are F and G (Fig. 3). Thus, MF = 35.2^ 2 - 8O 1 - 4) -^1 X 2 (I^ 22 ) = 215.6;
y 2 = 8.25 ft (2.515 m); M 0 = 30.8j; 2 - /2(1.2J 22 ) = 215.6; y 2 = 8.36 ft (2.548 m).
Alternatively, locate F by considering the area under the shear diagram between E and
F. Thus MF = 340.3 -^1 X 2 (1.2y 32 ) = 215.6; y 3 = 14.42 ft (4.395 m); yi = 22.67 - 14.42 =
8.25 ft (2.515m).
For symmetry, center the cover plates about midspan, placing the theoretical cutoff
points at 8 ft 3 in (2.51 m) from each support.
(a) Reinforced sectionPlate(b) Welding of cover platesFIGURE 4