Form: Assign Frame Mass
Every object contributes mass to the structure from the mass density of its material. Use the Assign menu > Frame > Line Mass command to assign additional line mass to a frame. Any additional mass assigned to a frame object is added to the object mass to give the total mass of the building. The additional mass might be used to account for partitions, cladding, and the like.
Note: The additional line mass is considered by SAP2000 only if the mass source is to be based on object masses and additional masses, not from a specified load combination. Also, the additional line mass is applied only in the three translational degrees of freedom.
Select the frame to be assigned line mass.
Click the Assign menu > Frame > Line Mass command to access the Assign Frame Mass form. Use the options on the form to specify the line mass and how the mass should be applied.
Line mass: Specify the translational mass per unit length in this area. The masses are entered in Force-Second2/Length2 units.
Options: Specify how the line mass will be assigned.
Add to existing masses: Adds the specified line mass to the frame. If one or more line mass assignments have already been made, this option increases the existing line mass.
Replace existing masses: Replaces the currently specified line mass, if any, with the new line mass. If no assignment exists, the new assignment is still made. This is the default option.
Delete existing masses: Deletes any and all line mass assignments made to the selected frame(s). When this option is selected, the items in the Line Mass area of the form are ignored when you click the OK button.
Note that the default option is Replace and that the program defaults to this every time the form is opened.
See Also