Question:
A cantilever beam AB is loaded by a uniform load q and a concentrated load P, as shown in the figure.
(a) Select the most economical steel C shape from Table F-3(a) in Appendix F; use q 5 20 lb/ft and P = 300 lb (assume allowable normal stress is s a 518 ksi).
(b) Select the most economical steel S shape from Table F-2(a) in Appendix F; use q 5 45 lb/ft and P = 2000 lb (assume allowable normal stress is
s a =. 20 ksi).
(c) Select the most economical steel W shape. Table F-1(a) in Appendix F; use q = 45 lb/ft and P = 2000 lb (assume allowable normal stress is s a = 20 ksi). However, assume that the design requires that the W shape must be used in weak axis bending, i.e., it must bend about the 2–2 (or y) axis of the cross section.
Transcribed Image Text:
Table F-1(a)
Properties of Wide-Flange Sections (W Shapes) USCS Units (Abridged List)
Flange
Weight
per
Designation Foot
W 30 x 211
W 30 x 132
W 24 x 162
W 24 X 94
W 18 X 119
W 18 x 71
W 16 x 100
W 16 X 77
W 16 X 57
W 16 X 31
W 14 X 120
W 14 X 82
W 14 X 53
W 14 X 26
W 12 X 87
W 12 X 50
W 12 X 35
W 12 x 14
W 10 X 60
W 10 X 45
W 10 x 30
W 10 x 12
W8 x 35
W 8 x 28
W8 X 21
W8 X 15
lb in² in.
211
132
162
94.0
119
71.0
100
77.0
57.0
31.0
120
82.0
53.0
26.0
87.0
50.0
35.0
14.0
60.0
45.0
30.0
12.0
Web
Area Depth Thickness Width Thickness
in.
0.775
0.615
35.0
28.0
21.0
15.0
62.2
38.9
47.7
27.7
35.1
19.0
20.8 18.5
35.3
24.0
15.6
30.9
30.3
29.5 17.0
22.6
16.5
16.8 16.4
9.13
15.9
7.69
25.0
24.3
25.6 12.5
14.6
12.2
10.3 12.5
4.16 11.9
6.16
4.44
17.6 10.2
13.3 10.1
8.84
10.5
3.54 9.87
10.3 8.12
8,24 8.06
8.28
8.11
0.705
0.515
14.5
0.590
14.3 0.510
13.9
0.370
13.9 0.255
in.
0.655 11.3
0.495
7.64
15.1
10.5
0.585
10.4
0.455 10.3
0.430
7.12
0.275
5.53
0.420
0.350
0.300
0.190
0.310
0.285
0.250
0.245
13.0
1.22
9.07 0.875
14.7
10.1
8.06
5.03
0.515 12.1
0.370
0.300
0.200
in.
1.32
1.00
10.1
8.02
5.81
3.96
8.02
6.54
5.27
4.01
1.06
0.810
0.810
8.08
0.640
6.56 0.520
3.97
0.225
0.985
0.760
0.715
0.440
0.940
0.855
0.660
0.420
0.680
0.620
0.510
0.210
0.495
0.465
0.400
0.315
Axis 1-1
1
in*
10300 665
12.9 757
5770 380 12.2 196
S r
in³
in.
5170 414 10.4 443
2700 222 9.87 109
1
inª
2190 231
7.90 253
1170 127 7.50 60.3
1380
190
881 123
541
245
1490
175
7.10
1110 134
7.00
758
92.2 6.72
375 47.2 6.41 124
88.6
186
138
6.24 495
6.05 148
77.8 5.89 57.7
35.3 5.65
8.91
341
248
170 32.4 4.38
53.8 10.9 3.90
43.1
740 118 5.38 241
391
64.2
5.18
285
45.6 5.25
14.9 4.62
56.3
24.5
2.36
66.7
4.39
116
49.1 4.32 53.4
16.7
2.18
127
3.51 42.6
31.2
98.0 24.3 3.45 21.7
75.3
18.2
3.49
9.77
48.0 11.8
3.29
3.41
Axis 2-2
S
in³
100
37.2
r
in.
68.4 3.05
24.0
1.98
3.49
2.25
44.9 2.69
15.8
1.70
35.7
2.51
26.9
2.47
12.1 1.60
4.49
1.17
67.5
29.3
3.74
2.48
14.3
1.92
3.55 1.08
39.7 3.07
13.9
1.96
7.47 1.54
1.19
10.6
0.753
23.0
2.57
13.3 2.01
5.75 1.37
1.10 0.785
2.03
6.63 1.62
3.71
1.26
1.70 0.876