Static Values to Cross-Sections
Think the steel profile cross-sections so that you are walking over them and they all seem to bend same like. Select a stronger profile, if it bends more, and the weaker, if the profile does not bend enough. We are all the time at the same deflection ratio. DIN 1025 - Euronorm 53-62 with HEB 100 steel shape is the starting point for the calculation. An example of HEB I-profile, but later the same to other cross-sections.
Bending case 1
Load of 1 kN is the weight of our own, at least the burden on our hands. HEB100 steel cross-section bends 0.518 cm (deflection ratio 1:1000), 1 kN load, the span of 518 cm. These numbers should not look having over-precision.
DIN 1025 - Euronorm 53-62
HEB 100 => F1:1000 = 0,518 cm
In the table are the static values for those who want to check the calculation by the traditional way. The sag of the girder consists of the weight of the girder and load. This is the only way to calculate the actual deflection at one time.
Profile L1000 σt Ix Wx Iy Wy
Nimike cm kN/cm2 cm4 cm3 cm4 cm3 kg/m A cm2
HEB100 518 2.2 450 90 167 33,5 20.4 26
HEB120 644 2.1 864 144 318 52,9 26.7 34
HEB140 761 2 1510 216 550 78,5 33.7 43
HEB160 868 2 2490 311 889 111 42.6 54.3
HEB180 968 2 3830 426 1360 151 51.2 65.3
HEB200 1062 2 5700 570 2000 200 61.3 78.1
HEB220 1150 2 8090 736 2840 258 71.5 91
HEB240 1235 2 11260 938 3920 327 83,2 106
HEB260 1316 2 14920 1150 5130 395 93 118
HEB280 1394 2 19270 1380 6590 471 103 131
HEB300 1468 2.1 25170 1680 8560 571 117 149
HEB320 1534 2.1 30820 1930 9240 616 127 161
The Young's modulus is 20 600 kN /cm2. In the literature also 20 600 - 21 000 kN/cm2. When a value of 21 000 kN/cm2, increases the L1000 length of HEB100 from 518 cm => 523 cm. Bending stress σt remains the same at both values. In practice, the tabled values are the same with both Young's modulus values, because 1% change in values does not mean much.
13.4.2015*9:10 (1054 - 441)
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