Assign - Area Mass

Form: Assign Mass

Every object contributes mass to the structure from the mass density of its material. Use the Assign menu > Area > Area Mass command to assign additional area mass to an area object. Note that the additional area mass is only considered by SAP2000 if you have specified that the mass source is to be based on object masses and additional masses, not from a specified load combination.

The additional area mass is applied only in the three translational degrees of freedom.

Select the area object to be assigned additional mass.
Click the Assign menu > Area > Area Mass command to access the Assign Mass form. Specify the mass and the assignment option:

- Area mass: Specify the translational mass per unit area in this region. The masses are entered in Force-Second2/Length3 units.
- Options: Choose an area mass assignment option:
- - Add to existing masses: Adds the specified area mass to the area object. If one or more area mass assignments have already been made, this option increases the existing area mass.
  - Replace existing masses: Replaces the currently specified area mass, if any, with the new area mass. If no mass assignment exists, the new assignment is still made. This is the default option.
  - Delete existing masses: Deletes any and all area mass assignments made to the selected area object(s). When this option is selected, the items in the Area mass area of the form are ignored when you click the OK button.

Note: The default option is Replace and the program defaults to this every time the form is opened.