Design Envelopes

[eissenhover]

Hello, I would like to consult you about an issue that I usually encounter in steel projects, there is a simple model as an example in the appendix, this system will carry a 6-ton water tank, the point I want to ask is; - After the analysis, all the controls are provided, but when I examine the deformations on the 3D model, while the maximum deformation is around 2-3 mm in all combinations (including steel and bet. design envelopes), the values that go up to 385 mm in modal E1-E2... combinations are in question. How should we interpret this? Should we act according to the steel design envelope?

 

[nurgulkaya]

Hello there; If you are examining the deformations for the relative displacements, the maximum joint displacement used in the relative story displacements is examined for the x and y directions, respectively, under Ex and Ey loading cases. If your aim is to look for deflection, the combinations for deflection in steel structures are checked from the combinations of G+Q and G+0.5S. You can see the deflection results from the steel element reports and the interface. If you do not have a multi-storey structure, you should find the nodal point that makes the most displacement for the relative translation from the interface for ex and ey and check it according to TBDY 2018. The values you see in Modal E1-E4 are the values before the normalization is applied due to the method, and although they have a meaning in themselves, they do not give you a meaning as you would use them in regulation controls. Combined and normalized versions of these values you see for each mode are available in EX and EY downloads. In summary: ignore the values you see in modal E1-E4. Good work.