Keywords
Imperfection Results Internal forces Warping torsion Stability analysis
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Automatically ignore curved c/t-parts when classifying cross-sections
The classification of cross-sections according to EN 1993-1-1 and EN 1993-1-5 can be carried out automatically in the RF-/STEEL EC3 add-on module. The maximum c/t ratios are specified in the standard for straight cross -section parts. There are no normative specifications for curved cross -section parts and therefore the cross -section classification cannot be performed for these cross -section parts.
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SHAPE-THIN | Cold-Formed Sections
SHAPE-THIN determines the effective cross-sections according to EN 1993-1-3 and EN 1993-1-5 for cold-formed sections. You can optionally check the geometric conditions for the applicability of the standard specified in EN 1993‑1‑3, Section 5.2.
The effects of local plate buckling are considered according to the method of reduced widths and the possible buckling of stiffeners (instability) is considered for stiffened sections according to EN 1993-1-3, Section 5.5.
As an option, you can perform an iterative calculation to optimize the effective cross-section.
You can display the effective cross-sections graphically.
Read more about designing cold-formed sections with SHAPE-THIN and RF-/STEEL Cold-Formed Sections in this technical article: Design of a Thin-Walled, Cold-Formed C-Section According to EN 1993-1-3.
Frequently Asked Questions (FAQ)
- For which programs is the STEEL Warping Torsion add-on module available?
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I design an eccentrically modeled wall beam in RF‑/STEEL Warping Torsion, which is loaded transversely with a distributed load. While the bending moments in the main program result in zero at the member start and member end due to the hinges, the RF‑/STEEL Warping Torsion add-on module displays moments at these locations, which incorrectly reduces the span moment.
How do I get the boundary moments equal to zero at this point? - How can I design any SHAPE‑THIN cross-section in detail in RFEM or RSTAB?
- When entering data in the RF‑/STEEL EC3 add-on module, I get the error message "Incorrect location of the intermediate lateral restraint". Why?
- How can I perform a lateral-torsional buckling analysis for unsymmetric steel cross-sections?
- What does the load application point in RF-/STEEL EC3 Warping Torsion refer to?
- To which axes refer the support rotations and support eccentricities in RF‑/STEEL EC3 Warping Torsion?
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What are the options in RFEM or RSTAB for determining the ideal elastic critical moment for any cross-sections and systems/loads?
Is it also possible to design flat steel (brackets, flat steel stringers of staircases)? - What is the difference between RF‑/FE‑LTB and RF‑/STEEL Warping Torsion? Both calculate with on the 7th degree of freedom.
- A moment distribution in STEEL Warping Torsion fails or the sign is changed from one x‑location to the next. What could be the reason for this?