Question
I was checking the cross-section properties of rolled cross-sections in SHAPE‑THIN and found out that there are discrepancies with the tables when determining the torsional constant It. How can this be explained?
![Roundup Function](/en/webimage/010182/3051809/01-en.png?mw=512&hash=65e98cfe859ce35a3e3e9da47a0ef9335401520e)
![Hybrid Cross-Section in SHAPE-THIN](/en/webimage/010292/3043707/01-en.png?mw=512&hash=65e98cfe859ce35a3e3e9da47a0ef9335401520e)
![Specifying Default Program in Project Manager](/en/webimage/010306/3042590/01-en.png?mw=512&hash=65e98cfe859ce35a3e3e9da47a0ef9335401520e)
![Cross-Section with "Swapped" Moments of Inertia](/en/webimage/010307/3034781/01-en.png?mw=512&hash=65e98cfe859ce35a3e3e9da47a0ef9335401520e)
![Effective Cross-Section in SHAPE-THIN 8](/en/webimage/006822/484232/DUENQ.png?mw=512&hash=96d43be20a4528cf741503961d2b0429d7f70ef4)
In SHAPE-THIN 8, the effective cross-section of stiffened buckling panels can be calculated according to EN 1993-1-5, Cl. 4.5.
The critical buckling stress is calculated according to EN 1993-1-5, Annex A.1 for buckling panels with at least 3 longitudinal stiffeners, or according to EN 1993-1-5, Annex A.2 for buckling panels with one or two stiffeners in the compression zone. The design for torsional buckling safety is also performed.
![Steels according to the Australian standard AS/NZS 4600:2005 in the material database](/en/webimage/006816/1584844/1356-en-png.png?mw=512&hash=71078e1c67a8e5709fa8b557bdb4e112b35390a6)
The material database in RFEM, RSTAB and SHAPE-THIN contains steels according to the Australian standard AS/NZS 4600:2005.
![SHAPE-THIN Cross-Section Properties Software | Section Properties of Thin-Walled Cross-Sections, Elastic and Plastic Design](/en/webimage/002829/2449167/11.jpg?mw=512&hash=3cf59b02a2883df92f903cd05cfcef162d84e31c)
- Modeling of the cross-section via elements, sections, arcs, and point elements
- Expansible library of material properties, yield strengths, and limit stresses
- Section properties of open, closed, or non-connected cross-sections
- Ideal section properties of cross-sections consisting of different materials
- Determination of weld stresses in fillet welds
- Stress analysis including design of primary and secondary torsion
- Check of c/t-ratios
- Effective cross-sections according to
- EN 1993-1-5 (including stiffened buckling panels according to Section 4.5)
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EN 1993-1-3
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EN 1999-1-1
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to DIN 18800-2
- Classification according to
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EN 1993-1-1
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EN 1999-1-1
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- Interface with MS Excel to import and export tables
- Printout report
![SHAPE-THIN Cross-Section Properties Program | Results - Distribution of Plastic Normal Stresses](/en/webimage/006863/1585833/000406-en-png-png.png?mw=512&hash=da8cd25c3f9555271a854551118ad92695f1eb4c)
All results can be evaluated and visualized in an appealing numerical and graphical form. Selection functions facilitate the targeted evaluation.
The printout report corresponds to the high standards of RFEM and rstab/rstab-9/what-is-rstab RSTAB. Modifications are updated automatically.