To Define Preferences for Force Balance Analysis
For this procedure you must be on the Preferences tab of the Analysis Definition dialog box and have selected Force balance under Type. A force balance analysis must meet the following conditions:
There is exactly one degree of freedom when there is no loadcell.
There are exactly zero degrees of freedom when a loadcell is introduced.
1. Click . The number of degrees of freedom are displayed.
2. Decrease the DOF to 0 as follows:
Click and select a rigid body as the lead body, then a set of follower bodies to be locked. The follower bodies stay fixed relative to the lead body during the analysis.
Click and select a connection. The connection's allowed movements are locked during the analysis.
Click and select a connection to be disabled.
Click to create a loadcell lock.
3. The name of the locked or disabled connection appears in the Locked entities list.
* 
Click to delete unwanted locking or disabling constraints from the list.
4. Check the degrees of freedom as described in step 1 after applying each constraint until you reach 0 DOF.
5. If you want the analysis to use the current configuration, click Current under Initial configuration.
6. If you want to use a previously created snapshot for the initial condition, click Snapshot under Initial configuration, and select a snapshot from the list.
7. Click to view the configuration.