Apply distributed mass across selected faces.
        Distributed mass can be applied using total mass or mass per area.
        - 
                On the Project Tree, open
                    the Analysis Workbench.
            
 
- 
                On the Analysis Workbench toolbar, click the 
 (Distributed mass) icon.
             
- 
                In the modeling window, select parts on the
                    model.
                
                    Note: Distributed mass can only be applied to faces.
                 
             
- Optional: 
                Select the Add tangent faces
                    check box.
            
 
- 
                In the drop down menu, specify Mass and Mass per area units.
            
 
- 
                Specify a value for Total mass or Mass per area.
            
 
- 
                Click OK.