Best way to do a Eurocode Wind Load analysis on a 3D Portal Frame Model

[Anonymous]

Hi, 

I'm designing a single span portal frame building and i want to apply wind loads in accordance with Eurocodes, UK NA. 

To date, i have established the model, which is made of a 9 portal frames incorporating 3 different spacing's, cladding panels, bracing etc. Now i understand from previous posts, that RSA can only do a Eurocode analysis on a 2D frame, with regular frame spacings to represent the building. 

This is a real shame as the wind analysis to Eurocode is a rather long process, so is there any way of simulating the analysis with a 3D model?  Theres been some discussion on this, but it seems theres no clear way to do this, so is it the case that you need to resort to undertaking the wind load analysis by hand, figure out the load distribution to each frame and input line loads to the frame to represent  the wind loads??

Any help or suggestions would be greatly appreciated, as our team is looking to use this package for building designs, but its a shame if the wind analysis cant be modelled in line with the codes as its one of the most time consuming tasks. 

[Pawel.Pulak]

Hi,

If you already have 3D model with claddings, some way to at least partially use automatic generation of wind loads according to BS-EN 1991 may be:

1/ extracting one frame from this model with Y=0, changing it to 2D frame and saving

2/ for such additional 2D model running automatic generation of wind loads specifying total depth of the structure corresponding to the real one

3/ running generation for specific frames (from specific wind load zones: edge, central)

4/ using the loads from calculation notes to manually define appropriate loads in your 3D model

5/ repeating steps 3/ and 4/ for various zones and frames

I know that such approach requires a lot of manual work to transfer loads from 2D to 3D model.

On the second screen capture you can see "3D generation" button - it enables automatic "extrusion" of 2D frame into 3D simultaneously with automatic generation of wind loads - but it works only for equal spacings of frames.

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Regards,