Page 109 - Handbook of Civil Engineering Calculations, Second Edition

1.92 STRUCTURAL STEEL ENGINEERING AND DESIGN

FIGURE 3

3. Record the properties of the beam section
Refer to the AISC Manual, and record the following properties for the W18 60; d
18.25 in. (463.550 mm); b f 7.56 in. (192.024 mm); t f 0.695 in. (17.653 mm); I 984
3
4
3
4
in (40.957 cm ); S 107.8 in (1766.84 cm ).
4. Select a trial section
Apply the approximation A 1.05(S – S WF )/d WF , where A area of one cover plate, sq.in.
2
3
3
(cm ); S section modulus required, in (cm ); S WF section modulus of wide-flange
3
3
shape, in (cm ); d WF depth of wide-flange shape, in. (mm). Then A [1.05(170.2 –
2
107.8)]/18.25 3.59 sq.in. (23.163 cm ).
2
Try 10 /8 in. (254.0 9.5 mm) plates with A 3.75 sq.in. (24.195 cm ). Since the
3
beam flange is 7.5 in. (190.50 mm) wide, ample space is available to accommodate the welds.