HEB100 Profile Calculation
The HEB100 cross-section in the picture has proven to be the right choice. The corresponding calculation can also be performed for other cross-sections.
Bending case 1
In many cases a permissible deflection is specified for a load‑bearing section, yet the section itself is not defined. In such calculations the deflection arising from the self‑weight of the section is frequently omitted. When determining the relevant static properties used to evaluate deflection, neglecting the contribution from self‑weight may lead to unforeseen issues in the intended application.
Engineering tables provide the static properties for each section type, and these values form the basis for calculating deflection under the applicable load case. In practice this is often carried out using a “generous design allowance”, which is assumed to include the deflection caused by the section’s own weight. However, in several cases I have reviewed, this aspect has simply been disregarded.
The table below for the HEB100 cross-section gives static values of the deflection, which takes into account the load and also the deflection caused by the beam's weight. Without forgetting the magnitude of the bending stress determined by the table at different spans. The tables presented elsewhere for strength calculation do not do this.
Span
The table below presents the values for the HEB100 cross‑section at a span of 520 cm, with the load F1 applied at mid‑span and a permissible deflection ratio of 1:1000. In this case, the bending stress is 2.2 kN/cm².
On the basis of this information, the remaining span lengths can be determined without resorting to traditional formula‑based calculations. This may be regarded as a natural way of deriving quantities from a known case – a method also employed by ancient cultures when estimating corresponding values. The approach is applicable not only to the same loading scenario but also to other comparable situations, although these are beyond the scope of the present discussion.
Bending Stress
HEB100 F1 1:1000 = 52 x 10 = 520 cm
(The ancient royal cubit 0.52 m)
Bending stress = 2.2 kN/cm2
Profile L1000 σt Ix Wx Iy Wy Area
Item cm kN/cm2 cm4 cm3 cm4 cm3 kg/m A cm2
HEB100 520 2.2 450 90 167 33,5 20.4 26
Deflection Ratio 1:1000
f= 520 cm / 1000 = 0.52 cm - f = 520 cm / 1000 = 0.52 cm
The deflection f is the span divided by the deflection ratio.
1 1:1250+
1 1 1:1000+
1 2 1 1:800-
1 3 3 1 1:623 (6.28 radians is full angle)
Pascalin kolmio
1.0 - 1.1(2) - 125
When the load is distributed uniformly along the entire length of the beam, the span may be increased by a factor of 1.1. The deflection ratio of 1:1000 remains unchanged, but the bending stress is reduced by approximately 25%. This principle applies equally to other cross‑sections. Please read more ==>
12.5.2026*8:30 (314 - 40559)
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