Select the Spectrum tab in the Spectrum Definition dialog to modify values for spectra definition.
A coordinate system in which spectra are presented or modified is located at the top of the dialog.
Select the values used for spectra definition in the Abscissa (X axis) and Ordinate (Y axis). Define the frequency and pulsation period on the x axis, and the acceleration, velocity and displacement values on the ordinate axis. Values presented on both axes can be presented on the logarithmic scale.
To define a new spectra, assign its name, define the damping value, and click Add. Define spectra points on the Points tab. Parameters defined on the Spectrum tab are retained when switching to the Point tab.
To delete a spectrum from the defined list, select the spectrum and click Delete.
To save a spectrum from the defined list, select the spectrum and click Save.
To open a spectrum from a file, click Open and navigate to the file.