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## Robot Structural Analysis

Contributor
Posts: 15
Registered: ‎06-30-2012

686 Views, 14 Replies
11-22-2012 04:58 AM
Hi, Suppose I need not apply wind loads to a tall building, say 60 meters. Should I calculate all the steps by hand, get the wind pressure and then input the value in WL, or there is any easier way where I can just input the coefficients values and other parameters and it will automatically calculate the wind loads? If I have to do it manually, who should I do it? Thanks
Product Support
Posts: 4,750
Registered: ‎12-17-2010

11-22-2012 05:05 AM in reply to: toha_mh

You need to do this manually. The easiest seem to define panels (outer walls or curtain walls) and apply load to them.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

Artur Kosakowski
Contributor
Posts: 15
Registered: ‎06-30-2012

12-18-2012 01:16 AM in reply to: Artur.Kosakowski

Hi, I calculated all the pressures manually according to ASCE 7-05. Now I have pressure for Windward, leeward, sidewalls, roofs from all directions (N-S), (E-W). But the problem is how can I enter these values into robot?

I defined four cladding on four sides of the building. Then what shoud I do? How many Wind Load cases should I define and how should I add the loads so that it works according to four cases oif ASCI?

Product Support
Posts: 4,750
Registered: ‎12-17-2010

12-18-2012 01:27 AM in reply to: toha_mh

I'm not familiar with the US wind code provisions but usually you need to define 4 wind load cases (from left, right, front and back). In each of them you should have positive pressure on one side of the building and negative one on the opposite one. The code should have also the part that describes wind load on the roof.

Artur Kosakowski
Distinguished Contributor
Posts: 107
Registered: ‎04-15-2011

12-18-2012 06:47 AM in reply to: Artur.Kosakowski

Dear Colleagues

Even thou I have to use Brazilian codes in my projects, I do use NV code (French code) to generate the loads in my structures. I believe that results are closer to reality than do hand calculations and load them in the structure.

My suggestion would be: try to use the French code to the structure and compare with your hand calculations results.

I am sure that they will be very similar and you gain a lot of time to spending them analying your structure.

Thanks

Gustavo

Contributor
Posts: 15
Registered: ‎06-30-2012

12-19-2012 02:55 AM in reply to: Artur.Kosakowski

Ok. I can do that. But ASCE says there should be 4 cases. Two of the cases are as follows:

Case 1: Full design wind pressure acting on the projected area perpendicular to each principal axis of the structure, considered separately along each principal axis.

Case 3: Wind loading defined in case 1, but considered to act simultaneously at 75% of the specified value.

Now, if I apply case 1 to all the faces and then make combination, it takes the maximum values from all the faces simultaneously in ULS+, which is more than 75% of the specified value that is required in case 3. Does that mean I don't have to define case 3, only case 1 will be enough?

Product Support
Posts: 4,750
Registered: ‎12-17-2010

12-19-2012 03:30 AM in reply to: toha_mh

Again I'm not the expert on the US code but shouldn't you:

1. Define 4 separate wind load cases with 100% value: X+, X-, Y+, Y-

2. Define next 4 separate load cases with 75% value: X+Y+, X-Y+, X-Y-,X+Y-

Finally you have 8 separate wind load cases to be combined with other loads (only one wind load case in a single combination).

Artur Kosakowski
Distinguished Contributor
Posts: 107
Registered: ‎04-15-2011

12-19-2012 03:56 AM in reply to: toha_mh

Dear toah_mh

Test with the French Code and, if necessary, change the requested parameters, or define new load cases.

Thanks

Gustavo

Distinguished Contributor
Posts: 121
Registered: ‎09-17-2012

12-19-2012 11:41 PM in reply to: toha_mh

Hi all colleagues

If possible to prepare your model in CBSpro , you can easily and automatically generate your wind loads for all directions using ASCE7-02 by define your suitable parameters then export to ROBOT

Note : see the attached capture

.

Thanks

Refaat

Product Support
Posts: 4,750
Registered: ‎12-17-2010