Wind loads applied to null areas

[rmedina1]

Hey, i've built up a fairly large model with a curved joist roof. It's composed of about 10 bays and i'm trying to model the roof using a series of null areas to try and approximate the roof's actual curvature. I'm also inputting my own wind loads, not using the wind coefficients or any automatic windload.

Now when i run the model even though i've applied the wind loads to the curved roof areas the structural frame doesn't respond to the loading. Do i have to attach the areas to each node of the roof individually, or do i need to give the roof some sort of property such as slab on deck.

I'm currently using ETABS v.8

any help would be appreciated.

 

[stressed]

You have to draw/mesh the null areas at joints to distribute load to the joints.

Alternatively, you can define your own deck membrane area, but with a material with no weight or stiffness (tiny modulus value), and ETABS will distribute area loads that you assign for wind, as distributed loads along the frames.