Surface wind load on a custom shape roof
How can you place surface wind loads, when you have a custom shaped flat roof instead of the standard types you can see in Eurocode?
How to do that
Create a load transfer surface to the roof with Draw polygon option at Edit load transfer surface dialog.
Open Create surface load dialog and choose Draw and Wind load option.
Set the parameters - load intensity will be calculated automatically:
Velocity pressure can be defined either manually or by clicking on the … and setting the parameters.
To calculate the zones and Cpe values click on the … at External pressure - Cpe. When defining the b and d values use the overall dimensions of the building of the current wind load direction. The zones will be calculated to cover this theoretical surface.
Select the Cpe you need and draw each zone one by one on your actual roof with Draw option.
Please note that the actual loads always need to be checked by the design engineer if they really accurate for the structure in hand.