Wind load simulation

[Anonymous]

Hi,

1- Can Any one explain to me why when I simulate wind load on a gable side steel frame (25 m wide and 9 m hight ) with wind speed 22 m/s I get such low wind pressure (highest 0.3 KPa),However, by hand calculation it is about 0.9 Kpa!

2- How can I specify that my building is in the country side , close to the sea or not?

[StefanoPasquini6790]

Hi rolad

Wind load simulation "IS NOT" a tool that calculate automatically the load distribution for country code wind cases, is a flow analysis applied in a virtual wind tunnel (shown on screen during the analysis). So the similarity between the country code wind load values and the wind load simulation it depend by the settings and can be very very different if you do wrong settings.

To make a wind load simulation very close to the country code values, you have to make your own spreadsheet to define wind speed ( that depend by all the parameters, for example building position, topography, exposition.....and so on) and wind profile. I suggest you to use constant wind speed profile and to searh in the forum one of my old post about this topic, there is an example and some tricks!

Greetings

[Anonymous]

Hi Stefano,

Thank u for your replay.

The wind speed is right I  define it using the post code of the building and I input it in the Robot.

I set up my building to be on the same level as the altitude of the building location .

Probably the wind profile I didn't understant. I keept it as it is. 1

I looked at your older posts....but honestly I get lost!

I attached my model. I would appriciate if u can spare some time and have a look.

[Anonymous]

Probably this is the answer

https://www.dropbox.com/s/ouqd7cbya5dq42b/calcolo%20vento.xlsx

[StefanoPasquini6790 · Accepted solution]

Yes, this is the answer for Algerian wind design code, you can edit the spresdsheet to fit to your wind loads design code.

Cheers

[Anonymous]

Hi need help please. I am trying to compare manual computation and the results from robot regarding wind load. What will be your inputs on the spreadsheet that will come from the generated loads from robot analysis? 

Spoiler

[Anonymous]

I don't know if I get your question exactly, but basically, I do the calculation of wind load on the spreadsheet first, get the effictive wind load, or the pressure based on the eurocode specifications and input this load into robot simulation.

[Anonymous]

Thank you for your help!I asked because I am making a study, if I could use Robot to compute for the wind load that will be used in designing structure. When I compare my manual calculation (ASCE-07 code) with the generated wind load on 2D frames, the values are not close enough. 

[Anonymous]

Hi,

I would suggest you read this discussion

http://forums.autodesk.com/t5/robot-structural-analysis/wind-loads-generation/td-p/5100254/page/2

I am working based on the Eurocode, I am not sure if I can help with other codes, anyway probably if you send your question as a new post, someone else could try and help you with it. you need to attach your comparison.

Best wish

[saclovitzky]

Hello Stefano,

Do you still have the spreadsheet for wind profile(eurocode)/

Regards

[StefanoPasquini6790]

Hi saclovitzky and forum members,

Here for you the spreadsheets for EU, IBC and US codes. 

Enjoy and share your comparison analysis between Robot CFD and code calculations. 

Cheers

[saclovitzky]

You're a legend Stefano Thanks!

[saclovitzky]

Hello Stefano do I need for the password on the spreadsheet, I cannot enter values on it, pls. see attached screenshot.

[StefanoPasquini6790]

Hi saclovitzky

type "x" in the country selector cell, as shown in this picture:

Cheers

[Anonymous]

Here is a small excel research of the comparison between ASCE7-10/EC1/NV65,

My findings,

1). factor to wind speed (coefficient to put in wind profiles) is:

- ASCE7-10: square root of Kz*Kd*Kzt*I

- EC1: square roof of Ce(z)

2) wind speed inputs in ASCE is different from that of EC1 and NV65.

- ASCE7-10: use wind speed for 3 sec gust speed: V(3sec)

- EC1/NV65: use wind speed for 10min gust speed (or 10min mean wind velocity): V(10min)

3) Both ASCE and EC1 gives similar result in term of global base shear. NV65 gives the smallest base shear given to the same inputs.

As cited in reference attached: according to ISO code: 1.05*V(1h) = V(10min) = 0.84*V(1min) = 0.67*V(3sec)

Excel link: http://www.mediafire.com/file/6r9fhgryyiavstp/ASCE-EC1-NV65-SSE-EXCEL_v1.07%282%29.rar

password: SSE

[Artur.Kosakowski]

Hi @Anonymous

Thank you for sharing it with the Robot forum community.

[msrmanag]

Actually, the file by this link has been deleted... I mean by this link: https://www.dropbox.com/s/ouqd7cbya5dq42b/calcolo%20vento.xlsx

[morten4MDUW]

Whether these wind simulation results are Fd or Fk ?

[mohamed.agrody]

does anyone happen to still have the file for algerian wind loads? it has been deleted

[okapawal]

@mohamed.agrody 

Pay attention that the code dependent wind load generation is available for 2D Frames model type only

You need to choose Algerian code for the snow/wind loads in Job Preferences