FAQ 004308 EN
10 February 2020
004308
When trying to calculate the design in RF-STEEL Surfaces, I receive Warning No. 1162 - Surface No. XX is of the type "Orthotropic" and cannot be designed. What does this Warning mean?
Answer
Orthotropic surfaces are non-linear and cannot be designed within the RF-STEEL Surfaces add-on module. It is possible to get a full stress analysis in RFEM for the orthotropic surfaces defined with the orthotropy type "constant thickness" and compared to limiting stresses manually. For all other orthotropy type, the program is not aware of the geometric properties for the surface at every FE mesh point which is needed to calculate stresses. An extensive and detailed FE model would need to be created. See FAQ 2468 for an example of this. Surface types need to be set to "standard" to be designed within the add-on module.
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CSA S16:19 Stability Considerations and the New Annex O.2
Structure stability is not a new phenomenon when referring to steel design. The Canadian steel design standard CSA S16 and the most recent 2019 release is no exception.
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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)
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Why are my steel members not being designed for stability in RF-STEEL AISC?
- My section is classified as Class 4 and non-designable in RF-/STEEL CSA. However, my manual calculation shows a different class. Why the difference?
- I have defined temperature loads, strain loads, or a precamber. As soon as I modify stiffnesses, the deformations are no longer plausible.
- Can the properties, such as B. the cross -section or the surface thickness as well as the material of a surface of an existing element for a new element?
- I am trying to manually check the deformations from the CRANEWAY add-on module. However, I obtain great deviations. How to explain the differences?
- What should be considered when using a failure of columns under tension in the RF‑/DYNAM Pro – Equivalent Loads add-on module?
- Why is there no stability analysis displayed in the results despite the activation of the stability analysis in RF‑/STEEL EC3?
- How can I model and design a crane runway girder with Dlubal Software?
- Is it possible to set user-defined values when viewing solid stress results?
- Why do I get large differences for the design of a longitudinally stiffened buckling panel in comparison with the German and Austrian National Annex?
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