Form: Mass Source
Use the Define menu > Mass Source command to bring up the Mass Source form and add, modify, or delete the load patterns and their scale factors used to calculate mass. SAFE offers modal analysis, and the mass used is calculated from a scaled combination of load patterns. The absolute value of the net load acting in the global downward Z direction is divided by the acceleration due to gravity and is used for the mass in each direction. Typically, only vertical modes should be considered in SAFE unless the SAFE model is an accurate representation of the entire structure.
To add a load pattern to the mass source, select a load pattern from the Load Pattern drop-down list adjacent to the asterisk, and then enter a scale factor. Do not include acceleration due to gravity in the scale factor; the program will do that automatically. The load patterns will be scaled by the specified factors and then added together to determine the net load in the downward direction, which is then used to calculate the mass.
To delete a load pattern from the mass calculation, click the arrow button adjacent to the load pattern to highlight the row and hit the delete key.
Uncheck the Ignore Lateral Mass check box if lateral masses are to be included.