Define Rigid Body Motion
Use the Rigid Body tool to simulate the dynamic motion of a body under the influence of forces and moments.
To represent rigid body motion, you need to define:
        - A local coordinate system
 - External forces and moment
 - Internal fluid traction and moment
 
- 
                From the Motion ribbon, click the Rigid Body tool.
                

Figure 1. - 
                Select surfaces and/or solids.
                Use the guide bar selectors to filter which entity type you can select.
 - On the guide bar, click DOF.
 - 
                Left-click on the model body to position the local coordinate system.
                Tip: Use snap points to position the triad on existing points, lines, surface centers, etc.
Reposition the coordinate system by left-clicking on a new point or entering center coordinates in the dialog.
 - In the dialog, define mass, external forces, external moment, and initial conditions.
 - 
                Define translational motion and stiffness/damping effects.
                
- 
                        Click the translation arrow on the triad widget in either of the three
                            direction.
                        

Figure 2. - Optional: In the dialog, disable the Active option to freeze (deactivate) translational motion in that direction.
 - Define stiffness and damping effects.
 - Press Esc.
 
 - 
                        Click the translation arrow on the triad widget in either of the three
                            direction.
                        
 - 
                Define rotational motion and stiffness/damping effects.
                
- 
                        Click the rotation arrow on the triad widget in either of the three
                            direction.
                        

Figure 3. - Optional: In the dialog, disable the Active option to freeze (deactivate) rotational motion in that direction.
 - Define stiffness, damping, and dyadic effects.
 - Press Esc.
 
 - 
                        Click the rotation arrow on the triad widget in either of the three
                            direction.
                        
 - 
                From the guide bar, execute the command in the following
                    ways:
                
- Click 
 to confirm your selection and remain in the
                            tool.This allows you to continue creating instances and helps you visualize and edit instances with the legend.
 - Click 
 to confirm your selection and exit the
                        tool. 
 - Click