Mass Participation Factor Results

For dynamic analyses, modal, and prestress modal analyses, if you select the Mass Participation Factors check box on the Output tab of the analysis dialog box the engine writes mass participation factor information to the summary file during a run. Immediately preceding the measure output for the analysis, the summary file contains a table with the same format as the frequency data for modal analyses. The columns of the table are:

• Mode—mode number

• Frequency—frequency of indicated mode

• Mass Participation Factor—indicator of the relative participation of the mode

• Effective Mass—percentage indicator of participation of mode. This is the ratio of the mass participation factor to the squared value of the total mass.

• Total Effective Mass—percentage indicator of participation of modes up to and including indicated mode. This is the sum of effective masses of modes up to and including indicated mode.

For a modal or a prestress modal analysis these quantities are calculated and recorded for translations in the WCS X-, Y-, and Z- directions and rotations about the WCS X-, Y-, and Z- axes.