JavaScript must be enabled in order to use this site.Please enable JavaScript in your browser and refresh the page. Frequency tab Used to specify commands to calculate the frequency using the Rayleigh method or by solving an eigenvalue problem. Rayleigh Frequency This option has no additional parameters Modal Calculation SettingDescription Consider Missing Mas Mode Check this option to include the missing mass procedure in the analysis for Steady State/Harmonic analysis. Parent topic: Add New Load Items dialog Related tasksRelated reference M. To calculate the structure frequency TR.34.2 Modal Calculation Command TR.34.1 Rayleigh Frequency Calculation