Restraints

Form: Joint Assignment - Restraints

Assigning a support to a joint object is meaningful only if structural objects are connected to the joint object. Otherwise, the joint support will support air, so to speak; that is, it will not support anything. Either the joint object must be connected directly to a structural object, or it must be on top of a floor-type shell object that ETABS can automatically mesh.

Note that restraints are always specified in the global coordinate system.

Select the joint object(s) to which the restraint(s) is to be assigned.
Click the Assign menu > Joint > Restraints command to access the Joint Assignment - Restraints form.
- Restraints in Global Directions options. These check boxes identify the six possible degrees of freedom available for a joint object. When a check box is checked, that degree of freedom is restrained. When a check box is unchecked, that degree of freedom will be unrestrained, assuming that the degree of freedom has been designated as active for the model.
- Fast Restraints options. Choose one of the following four buttons to quickly set the restraint conditions. Note that when one of the buttons is checked, the check boxes in the Restraints in Global Directions area of the form become checked or unchecked, depending on the selection made.
- - Fixed base restraint button. Click this button to restrain all six degrees of freedom.
  - Pinned base button. Click this button to restrain all three translation degrees of freedom and to specify that all three rotation degrees of freedom be unrestrained.
  - Roller support button. Click this button to restrain only the Z translation. All other degrees of freedom are unrestrained.
  - No support button. Click this button to specify that all degrees of freedom are unrestrained.

Click the Apply button to apply the assignment and leave the form open to allow assignment to another set of selected objects; when all assignments have been made, click the Close button to close the form. When the Apply button is used, the form will remain open until it is closed by clicking the Close button.

If only one assignment is being made to only one set of selected objects, the OK button can be used to both apply the assignment and close the form.