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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Three Equal Spans » Aluminum I Beam » 4.00 × 2.311
Aluminum I Beam | Single Span | Two Equal Spans | Three Equal Spans | Four Equal Spans

For a simply supported beam in three equal spans, we compute the displacement at the middle of the first and the third spans, and the maximum normal stress stress_max occuring at the second and third supports of the beam.
The tabulated data listed in this page are calculated based on the area moment of inertia (Ixx = 5.62 in4) for the 4.00 × 2.311 Aluminum I Beam and the typical Young's modulus (E = 1.015 × 107 psi) of Aluminum Alloys. Note that the typical yielding stress Yield of Aluminum Alloys can range from 4061 to 7.614 × 104 psi. The purpose of this page is to give a rough estimation of the load-bearing capacity of this particular beam, rather than a guideline for designing actual building structures. Please check your local building codes for regulatory requirements.
Note: The weight of the beam itself is not included in the calculation.
L = 3 ft
L = 5 ft
L = 10 ft
L = 15 ft
L = 20 ft
L = 25 ft
L = 30 ft
L = 40 ft
L = 50 ft
   
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 3.85 × 10-5 8.88
3.00 5.00 × 10-5 11.5
4.00 6.67 × 10-5 15.4
5.00 8.34 × 10-5 19.2
6.00 1.00 × 10-4 23.1
7.00 1.17 × 10-4 26.9
8.00 1.33 × 10-4 30.7
9.00 1.50 × 10-4 34.6
10.0 1.67 × 10-4 38.4
20.0 3.34 × 10-4 76.9
30.0 5.00 × 10-4 115
40.0 6.67 × 10-4 154
50.0 8.34 × 10-4 192
60.0 0.00100 231
70.0 0.00117 269
80.0 0.00133 307
90.0 0.00150 346
100 0.00167 384
200 0.00334 769
300 0.00500 1150
400 0.00667 1540
500 0.00834 1920
600 0.0100 2310
700 0.0117 2690
800 0.0133 3070
900 0.0150 3460
1000 0.0167 3840
2000 0.0334 7690
3000 0.0500 1.15 × 104
4000 0.0667 1.54 × 104
5000 0.0834 1.92 × 104
6000 0.100 2.31 × 104
7000 0.117 2.69 × 104
8000 0.133 3.07 × 104
9000 0.150 3.46 × 104
1.00 × 104 0.167 3.84 × 104
1.98 × 104 0.330 7.61 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 2.97 × 10-4 24.7
3.00 3.86 × 10-4 32.0
4.00 5.15 × 10-4 42.7
5.00 6.44 × 10-4 53.4
6.00 7.72 × 10-4 64.1
7.00 9.01 × 10-4 74.7
8.00 0.00103 85.4
9.00 0.00116 96.1
10.0 0.00129 107
20.0 0.00257 214
30.0 0.00386 320
40.0 0.00515 427
50.0 0.00644 534
60.0 0.00772 641
70.0 0.00901 747
80.0 0.0103 854
90.0 0.0116 961
100 0.0129 1070
200 0.0257 2140
300 0.0386 3200
400 0.0515 4270
500 0.0644 5340
600 0.0772 6410
700 0.0901 7470
800 0.103 8540
900 0.116 9610
1000 0.129 1.07 × 104
2000 0.257 2.14 × 104
3000 0.386 3.20 × 104
4000 0.515 4.27 × 104
5000 0.644 5.34 × 104
6000 0.772 6.41 × 104
7000 0.901 7.47 × 104
7130 0.918 7.61 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 0.00476 98.7
3.00 0.00618 128
4.00 0.00824 171
5.00 0.0103 214
6.00 0.0124 256
7.00 0.0144 299
8.00 0.0165 342
9.00 0.0185 384
10.0 0.0206 427
20.0 0.0412 854
30.0 0.0618 1280
40.0 0.0824 1710
50.0 0.103 2140
60.0 0.124 2560
70.0 0.144 2990
80.0 0.165 3420
90.0 0.185 3840
100 0.206 4270
200 0.412 8540
300 0.618 1.28 × 104
400 0.824 1.71 × 104
500 1.03 2.14 × 104
600 1.24 2.56 × 104
700 1.44 2.99 × 104
800 1.65 3.42 × 104
900 1.85 3.84 × 104
1000 2.06 4.27 × 104
1780 3.67 7.61 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 0.0241 222
3.00 0.0313 288
4.00 0.0417 384
5.00 0.0521 480
6.00 0.0626 577
7.00 0.0730 673
8.00 0.0834 769
9.00 0.0938 865
10.0 0.104 961
20.0 0.209 1920
30.0 0.313 2880
40.0 0.417 3840
50.0 0.521 4800
60.0 0.626 5770
70.0 0.730 6730
80.0 0.834 7690
90.0 0.938 8650
100 1.04 9610
200 2.09 1.92 × 104
300 3.13 2.88 × 104
384 4.00 3.69 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 0.0761 395
3.00 0.0989 512
4.00 0.132 683
5.00 0.165 854
6.00 0.198 1020
7.00 0.231 1200
8.00 0.264 1370
9.00 0.297 1540
10.0 0.330 1710
20.0 0.659 3420
30.0 0.989 5120
40.0 1.32 6830
50.0 1.65 8540
60.0 1.98 1.02 × 104
70.0 2.31 1.20 × 104
80.0 2.64 1.37 × 104
90.0 2.97 1.54 × 104
100 3.30 1.71 × 104
121 4.00 2.07 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 0.186 617
3.00 0.241 801
4.00 0.322 1070
5.00 0.402 1330
6.00 0.483 1600
7.00 0.563 1870
8.00 0.644 2140
9.00 0.724 2400
10.0 0.804 2670
20.0 1.61 5340
30.0 2.41 8010
40.0 3.22 1.07 × 104
49.7 4.00 1.33 × 104
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 0.385 888
3.00 0.500 1150
4.00 0.667 1540
5.00 0.834 1920
6.00 1.00 2310
7.00 1.17 2690
8.00 1.33 3070
9.00 1.50 3460
10.0 1.67 3840
20.0 3.34 7690
24.0 4.00 9220
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 1.22 1580
3.00 1.58 2050
4.00 2.11 2730
5.00 2.64 3420
6.00 3.16 4100
7.00 3.69 4780
7.59 4.00 5180
Aluminum I Beam: 4.00 × 2.311 (4.00 inch tall × 2.311 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
2.31 2.97 2470
3.00 3.86 3200
3.11 4.00 3320
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Information, coverage of important developments and expert commentary in manufacturing.

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