Form: Ground Displacement
A generalized displacement is a linear combination of displacement degrees of freedom from one or more joints. Generalized displacements are primarily used for output purposes, except that they can also be used to monitor a nonlinear static analysis.
Note: Displacements should be applied to restrained joints only. The joint restraint should be in the degree of freedom in which the load is placed.
Select the joints to be assigned joint displacement loads.
Click the Assign menu > Joint Loads > Displacements command to access the Ground Displacements form.
Load Case Name drop-down list. Select the load case to which the displacement load is being added. Alternatively, click the + (plus symbol) beside the drop-down list to access the Define Loads form; use the form to define a load case that will then be available in the drop-down list.
Units drop-down list. If necessary, use the Units drop-down list to change the units on the form.
Displacements edit boxes. Enter values for the Translations and Rotations in the appropriate edit boxes.
Coordinate System drop-down list. Select the coordinate system for the load from the drop-down list.
Options. Specify how the load will be applied.
Add to Existing Loads: Adds the specified displacement to the joint. If one or more displacement assignments have already been made, this option increases the existing displacement, assuming that a positive displacement is being specified.
Replace Existing Loads: Replaces the currently specified displacement, if any, with the new assignment. If no assignment exists, the new assignment is still made. This is the default option.
Delete Existing Loads: Deletes any and all displacement assignments made to the selected joint(s). When this option is selected, the items in the Displacements area of the form are ignored when the OK button is clicked.
The screen will refresh with a graphical representation of the load assigned on the selected joints.
Example: Assignment of displacement loads is demonstrated in Problem G.
See Also
Display- Show Load Assigns - Joints