Wind Load pattern defined in Etabs

[Huong83]

I am modelling a building with concrete slab, column and shear walls (no boundary walls)
I try to apply the wind load in Etabs model with the wind load pattern already in Etabs.
My questions are:
- The wind load will be applied laterally or vertically or both ?
- Which building elements are the wind load applied to ?
- Windward and Leeward coefficient are added together to give total wind load in Etabs ?
- Internal wind pressure coefficient not included ? or they were assumed to cancel.
- What happened with the building with a big opening ?
- I tried a simple model with and without the boundary walls. I ended up the total wind reaction the same in both.

Thanks.

 

[johnbridge231]

There are 2 ways to appy a wind load automatically in ETABS:

1. Use rigid or semi-rigid diaphragms in youyr model and create a load case of wind type with the Auto Lateral Load oiptions assigned. Then the program will only apply th computed load at the center of the diaphragms, considering the wind coefficients provided and assuming that the exposure area coincides with the vertical surface between successive stories at the perimeter of the plan.

2. Assign wind coefficients manually directly to wall objects.

These procedures are described analytically in the Lateral Loads Manual under the help menu.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[tngv752]

Thanks John,
First way = wind load applied on the building laterally without vertically. We get the same laterally wind load even if the vertical walls can be modelled or not. The wind load on the building sides assumed to be cancelled.
Second way = can be manually applied wind load in any objects we want including walls, floors, beams and columns ?

 

[johnbridge231]

Exactly.
Second way= wind pressure coefficient is applied to walls (not wind load).

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[MrHershey]

Second way is not just walls. You can also apply to floors/ramps (know this from experience).

I believe there are open-structure wind coefficients you apply to frame elements as well, though I have never done this.