RAM Frame automatically calculates the Weight, Mass, Center of Mass, and Mass Moment of Inertia of each diaphragm using information obtained from RAM Modeler.

The default value for eccentricity is taken as 5% of the building (or diaphragm) dimensions unless the default Building Code is the Canadian Code, in which case the default value for eccentricity is 10%. The user can specify any value of eccentricity desired, either by entering a new value for % Eccentricity and selecting Recalculate, or by entering a value of Eccentricity directly into the table. For models that consist of lateral frame members only, this information must be entered manually if the load case generators are to be used.

With the Loads - Masses command, you can accept the values calculated by the program or enter your own values. The Load Masses dialog box is first displayed in a "Read Only" format with the Use Calculated Values option button selected. To change these values, you must first click the Use Specified Values button. Cells in the spreadsheet can then be highlighted and the values within them modified.

Note that Diaphragm Masses are tabulated according to stories with associated diaphragms. If there is any mass found not associated with any diaphragm (such as mass components of point or line loads stayed outside of any diaphragm, or self masses from members not connected to any diaphragm), they are referred to as "None" mass component of corresponding story and they are also listed in the table.

Whether using calculated values or specifying values, the last column in the spreadsheet, Combine To, is available for user input. Combine To indicates whether the mass of a given diaphragm (and any seismic loads associated with it) is to be combined with that of another diaphragm. The user should select diaphragm - story name from the pull-down menu if mass at a particular level is required to be combined to another diaphragm. Similarly, None mass components of a story (if applicable) can be combined to any diaphragm at the same story or at other stories. Note that None mass component of a story can not be combined to a None mass component of another story. Calculated diaphragm mass properties for the latest configuration can always be reviewed in Criteria, Mass and Exposure Data report.

This dialog is primarily intended to be used with Rigid and Pseudo-Flexible diaphragms. The only exception is that the values indicated in the dialog (either calculated or user specified) are also used for Semirigid diaphragms if the Uniformly Distribute Total Mass Over Diaphragm option is selected in Story Diaphragm dialog. In this case, the program uses the values reported in the dialog for associated semirigid diaphragms. Thus, any merged\lumped configuration set by Combine To is also effective for Semirigid diaphragms.

Click the OK button to affirm the changes made. Click Cancel to return to the settings as they existed prior to making changes.

The Wall self-mass is included if the Wall self-weight option has been selected in the Criteria-Self-Weight command in the RAM Manager. Similarly, member self masses for beams, columns and slabs\decks can also be included if corresponding options in the Criteria-Self-Weight command are selected.