Form: Frame Initial P-Delta Forces
Important: This is a specialized option intended primarily as a substitute for a true P-delta analysis. We recommend that you use nonlinear static analysis to calculate P-delta effects.
Select the straight frame to be assigned a P-Delta load.
Click the Assign menu > Frame > P-Delta Forces command to access the Frame Initial P-Delta Forces form.
Coordinate System drop-down list. Specifies the coordinate system for the projected force.
Initial Force options and edit boxes. Enter a value for the P-Delta axial force acting on the selected object(s). Use the edit boxes to specify the actual axial force (Force edit box) or a component of the axial force (X, Y, or Z Global Projection edit box).If the component of axial force method is used, also use the Coordinate System drop-down list to specify the coordinate system for the axial force, as necessary.
Option. Specify how the load is to be applied.
Add to existing force: Adds the specified force to the selected object. If one or more force assignments have already been made, this option increases the force, assuming, of course, that a positive force is being specified.
Replace existing force: Replaces the currently specified P-Delta force, if any, with the force. If no assignment has been made, the new assignment is still made. This is the default option.
Delete existing force: Deletes any and all P-Delta force assignments made to the selected object(s). When this option is selected, the items in the Initial Force area of the form are ignored when the OK button is clicked.
Note: More than one P-Delta load can be assigned to an individual frame member.
See Also