| Load Case |
States the Label of the load case being defined. |
| Direction |
Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts. |
| Mean Roof Height/Structure Height |
Building height used in the calculation of Gust Response and Pressure Coefficients (It is not used in the calculation of the actual exposed area). Building Height refers to the height of the building above ground level as defined in the Ground Level dialog. If parapet height is to be included, it is defined in the Exposure dialog.
You have the option to override the program’s selection of Building Height by selecting the third option, Use, and entering a value in the corresponding edit box.
See building code for more information.
|
| Design Type
|
Two design types are provided:
- design for the
serviceability limit state
- design for the
ultimate limit state
|
| Natural Frequency
|
Two options are provided:
- a user-defined
frequency
- program calculated
(dominant) natural frequency
|
| Wind Characteristics: X-Dir/Y-Dir
|
For each direction, X and Y, the following parameters
are required:
| Setting | Description |
|---|
| Design Wind Speed: Windward
|
you either defines a constant wind speed
(i.e., wind speed is constant over the height of the building) or it varies
with height. For the latter case, you must provide a file (with an extension of
.wnd) with wind speeds tabulated at
different heights. If the model is defined with English units, then the file
should include values with foot and mph units for the height and speed,
respectively. Otherwise, it should be in terms of meters and m/s.
For example, a file named
MyWindProfile.wnd and the contents of
the file is as follows:
// wind profile (height versus wind speed)
0.0 35.0
10. 45.0
20. 60.0
|
| Design Wind Speed: Leeward
|
It is always assumed to be constant.
|
| External Pressure, Cp,e
|
External pressure coefficients are required for
both windward and leeward surfaces. See section 5.4.1 in the building code.
|
| Dynamic Response Factor (Cdyn)
|
Either type a value for
Cdyn or select the option for the program to
calculate Cdyn based on Iz type (turbulence
intensity) and ratio of structural damping to critical damping.
|
|
