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heron1 November 13, 2009 07:29

Wind Load on Short Structures
 
Hi!!
I'm an engineering student. I've to study, with CFD, the wind load (and its fluctuations)on a structure less than 10 meters tall , dipped in an air flow of max velocity 14 m/s.
Can you help me about choosing wind velocity profile, type of simulation, boundary conditions...?

Thanks :)

george85 May 3, 2012 17:35

I am also interested in this.
But nobody seems to be answering.

http://imageshack.us/photo/my-images/252/11637918.jpg/I made a wind analysis for particular wind direction in Solid Works:

http://imageshack.us/f/252/11637918.jpg/http://imageshack.us/f/252/11637918.jpg

I made a small predictions, of what I am not sure it it is correct:

Then I took the maximum pressure (both compression and suction values) on the surface and pretended that I have those two values on the whole surface. Then I will take the part with the largest cell area in my space frame structure and do the following:

maximum compressional pressure on the surface: 1,013 KN/m2
largest cell area in my space frame structure: 0.34 m2

Nodal force on the vertices of the largest cell area in my space frame structure:
1,013 KN/m2 x 0.34m2 = 0,344 KN / 3 (because each cell area has 3 nodal forces) = 0,11 KN
So I will load each node with compressional nodal force of 0.11KN. This will be the first Load case.


The second load case will be with suction:

maximum suction pressure on the surface: -1,012 KN/m2
largest cell area in my space frame structure: 0.34 m2

Nodal force on the vertices of the largest cell area in my space frame structure:
-1,013 KN/m2 x 0.34m2 = 0,344 KN / 3 (because each cell area has 3 nodal forces) = -0,11 KN

So the inner nodes will have 6 x +/- 0,11KN (because 6 triangles rely on the same node), and the outer ones will have 3 x or 1x +/- 0,11KN (depending on the position).

Of course I am planning to take another 17 of them (according to 18 directions of the wind rose).
My idea was just to get 2 load cases from each wind direction - therefor 32 load cases (16 of suction, and 16 of compression).

Any comments on this?

Can this be done like that?


Thank you.

So I will load each node with suctional nodal force of 0.11KN.




Is this the way to do it?

Boris_M May 4, 2012 15:01

I'm not quite sure if this is a fluid flow simulation question or a structural analysis question?

I cannot help with the structural an if this is a fluid flow then please explain a little more in detail.

Boris

george85 May 4, 2012 15:18

It's both.

But I guess what bothers us, is how to translate the results we got from the fluid flow simulation analysis (impact (pressure) of an air, on the surface) to structural analysis.

Sorry for disturbance.

Boris_M May 4, 2012 15:46

For SW there is a link to the structural calculation where you can transfer the pressure loads to the sturctural analysis.
See in the menu "Flow Analysis" and then "Tools".

Boris

george85 May 4, 2012 15:58

Thank you for the reply Boris.

You mean start the Solid Works Help, and then search for: "Flow Analysis" -> "Tools".

Or?

Boris_M May 4, 2012 16:01

No, there should be a point in the menu bar called "Flow Analysis", maybe it is named differently in SW Flowsimulation.

Boris


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