For a cross-section from the cross-section library of RFEM/RSTAB, the stresses calculated with RF‑/STEEL differ from the stresses of the same cross-section calculated with SHAPE‑THIN. What is the reason?


In RF‑/STEEL, the stresses are calculated on stress points of a cross-section. The stress points defined for the cross-section can be displayed in the details of the cross-section. For the cross-section shown in Figure 01, the stress points are defined along the cross-section. Thus, the stress points (here, Stress Points 1 and Stress Point 9) are also available in the roundings.
In SHAPE‑THIN, you can only calculate the stresses on elements. It is not possible to calculate the stresses on the point elements that are used to model irregularities in the cross-section geometry, such as roundings and so on. The stress points of the SHAPE‑THIN cross-section are displayed in Figure 02. In the case of the cross-sections with point elements, minor deviations in stresses may thus occur due to the different stress points.
Furthermore, SHAPE‑THIN provides the option to calculate the stresses for the most unfavorable element edges or for element center lines only. In RF‑STEEL, the stresses are calculated exclusively on the stress points.


Stress Cross-section library Point element Element Stress point Element edge Element center line

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Cross-Sections Thin-Walled

Stand-Alone Program

Properties and stresses of thin-walled and cold-formed cross-sections

Price of First License
1,450.00 EUR
RFEM Steel and Aluminum Structures

Add-on Module

Stress analysis of steel surfaces and members

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RSTAB Steel and Aluminum Structures
STEEL 8.xx

Add-on Module

Stress analysis of steel members

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850.00 EUR