Handbook of Civil Engineering Calculations

FIGURE 38

4. Try a single stiffener plate
   Using the plate in Fig. 39, which is 3.5 x 0.25 in (8.89 x 0.635 cm), the moment of inertia
   of the stiffener about the face of the web is

0.25 in x (3.5 in)^3

4= ^ = 3.57 in

4

> 2.34 in

4

o.k. (148.6 cm

4

> 97.4 cm

4

) o.k.

Related Calculations. This procedure is the work of Abraham J. Rokach, MSCE,

Associate Director of Education, American Institute of Steel Construction. SI values were

prepared by the handbook editor.

DETERMINING THE DESIGN MOMENT

AND SHEAR STRENGTH OFA BUILT-UP

WIDE-FLANGE WELDED BEAM SECTION

For the welded section in Fig.37a (selected from the table of Built-Up Wide-Flange Sec-
tions in Part 3 of the AISC LRFD Manual), determine the design moment and shear
strengths. Bending is about the major axis; Cb = 1.0. The (upper) compression flange is
continuously braced by the floor deck. Steel is A36.

Calculation Procedure:

1. Check the beam compactness and flange local buckling

Stiffeners

Web

FIGURE 39

Stiffener

Web