Definition of direction of spectral analysis (rotated)

[joverac]

HI, I'm using Revit and Robot integration and I have a problem. I have a model in Revit that is rotated, respect to the axis. When I export this model to Robot Structural, the models takes the axis of Revit and the rotation of the model (aproximately 20º) . I don't have problem with use the rotated model but I need to apply spectral analysis in the direction of the resistant elements. How can I rotate the application of spectral analysis?

[Artur.Kosakowski · Accepted solution]

In order to get correct results you need to rotate the model and have the directions of seismic/spectral excitations parallel to the global coordinate axes. 

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[Rafal.Gaweda]

See webinar 7, slide 11

[joverac]

I did That before in other structure but I lost the integration with Revit. Is it possible to rotate the direction of spectral application?

[Artur.Kosakowski]

It is possible by entering the appriopriate values in the direction fields but this is not recommended as the results may be incorrect. 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[joverac]

Well, In that case I can't apply a different direction of seismic analysis than x and y, for example 45º or 30º. I think is a good idea considere this in next versions.

[Artur.Kosakowski]

According to my knowledge the by principle this kind of analysis allows you to either:

- have fixed directions and be able to rotate a model (like in RSA)

- be able to enter model with one orientation only and rotate the directions

but you cannot have both at the same time. 

[memoalcr]

So if a code asks that the horizontal seismic excitation is the vector sum of 100% in the X direction and 30% in the Y directions this is where one defines X: 1 and Y: 0.3 (see image); correct?

[Artur.Kosakowski]

Hi @memoalcr

Correct.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.