Form: Surface Loads
Use the Assign menu > Load Data > Surface Loads command to assign surface loads (force/area) in the gravity (negative Z) direction to a selected area object.
Select one or more area objects in the datum plane (not walls or ramps).
Click the Assign menu > Load Data > Surface Loads command to access the Surface Loads form. On that form, select and enter data in the following categories:
Load Pattern Name: Select a previously defined load pattern from the drop-down list. The specified loads will be associated with this load pattern.
Load Direct: Select the load direction from the drop-down list.
Uniform Loads: Enter a value for the uniform surface load in the selected Load Direction.
Nonuniform Loads: Values entered in this area define a surface load that can vary linearly in each gradient direction. Select a previously defined coordinate system (excluding the UCS) from the drop-down list to define the x and y variables in the load equation. Enter a value in the A edit box to indicate how much the magnitude of the load changes per unit of distance parallel to the X axis. Enter a value in the B edit box to indicate how much the magnitude of the load changes per unit of distance parallel to the Y axis. Enter the magnitude of the surface load at the coordinate system origin into the C edit box. For additional information on nonuniform loads, please consult the “Load Patterns” chapter in the Analysis Reference Manual (see the Help menu > Documentation command, Manuals directory).
Options:
Add to existing loads: Adds the specified surface loads to the area object. If one or more surface load assignments have already been made, this option increases the total surface load on the object, assuming you specify a positive load.
Replace existing load: Replaces the currently specified surface loads, if any, with the new surface load assignment. If no assignment exists, the new assignment is still made. This is the default option. Note that only the loads in the load pattern that is specified are replaced.
Delete existing loads: Deletes any and all surface load assignments made to the selected area object(s). When this option is selected, the items in the Uniform and Nonuniform Loads areas of the form are ignored when you click the button. Note that only the loads in the load pattern that is specified are deleted.
The assignment will appear graphically on the screen. To remove the display, click the Assign menu > Clear Display of Assigns command.
Note: If both uniform and nonuniform loads are specified at the same time, they are additive.