Additional Form: Wind Exposure Width Data
Use the Wind Load Pattern - {Code} form to review and modify the parameters for the specified wind load. The options on the form depend on the code selected in the Auto Lateral Load drop-down list on the Define Load Patterns form.
The code-specific forms share the following areas, although the specific parameters in a given area may vary from form to form:
Exposure and Pressure Coefficients options. Choose an option to define these coefficients:
Exposure from Extents of Rigid Diaphragms option. If this option is selected, provide values for the Wind Direction Angle, Windward Coeff. and Leeward Coeff. This option allows the same wind load to be applied each time the load case is assigned.
Exposure from Shell Objects options. If this option is selected, the Wind Exposure Parameters area becomes inactive. In that case, use the Assign menu > Shell Loads > Wind Pressure Coefficients command to specify the windward and leeward coefficients when the wind load is assigned to a shell object. This option allows wind load coefficients and wind direction to be applied on an object-by-object basis.
Exposure from Frame and Shell Objects options. If ASCE 7-02 is selected as the Auto Lateral Load on the Define Load Patterns form, this area is added to the Wind Load Pattern - {Code} form. When this option is selected, choose to apply loads to Shell Objects, or Frame Objects (Open Structure), or both. This allows specification of wind loading on open structures [i.e., choose the Include Frame Objects (Open Structure) option only]. With an option(s) selected, specify the parameters in the Wind Coefficients area on the form.
Wind Exposure Parameters
Wind Directions and Exposure Widths - Modify/Show button. Click this button to access the Wind Exposure Width Data form. The spreadsheet is inactive and available for review only when the Exposure Set Width is Auto Calculated form Diaphragm Extents by the Program option is selected.
Select the Exposure Set Width is User Defined option to allow manual manipulation of the data.
The Direction Angles (use semicolon as separator) edit box can be used to specify the direction of the wind load. Multiple angles can be specified, separated by semicolons. The angels are measured relative to the X axis.
Use the edit boxes to specify the Story and Diaphragm ID to which wind load is being applied. Also specify the Width and Depth of the diaphragm, and X and Y coordinates on a diaphragm-by-diaphragm basis. Right click in a cell to Cut, Copy, and Paste data within the spreadsheet area. Standard Windows Copy and Paste commands can be used to copy and paste data into the spreadsheet from another program, such as Excel, assuming that the original data has the appropriate tabular format.
The Add Row button can be used to add a data row and the Delete Row(s) button can be used to delete a row. The Sort Rows button will sort the rows of data based on the Story ID.
Wind Coefficients. Specify or select values for code-specific wind coefficients.
Exposure Height. Select the appropriate story levels from the Top Story and Bottom Story drop-down lists to define the Exposure height. If the Include Parapet check box is checked, enter a value in the Parapet Height edit box.
Note: Please refer to the Automated Lateral Loads manual for information about the code-specific parameters (Help menu > Documentation > Manuals > Lateral Loads Manual command).
Access the Wind Load Pattern - {Code} form as follows:
Click the Define menu > Load Patterns command to access the Define Load Patterns form.
Type a unique name for the load pattern in the Load edit box, select Wind from the Type drop-down list, and select an option other than None or User Load from the Auto Lateral Load drop-down list.
Click the Add New Load button
Highlight the newly define load pattern in the display area and click the Modify Lateral Load button.
After a Wind load pattern has been defined as described above, highlighting the name of the previously defined pattern and clicking the Modify Lateral Load button will also display the form.