PSDCOM
PSDCOM, SIGNIF, COMODE, , ForceType
Specifies the power spectral density mode combination
method.
SIGNIFCombine only those modes whose significance level exceeds the
SIGNIFthreshold. For PSD response (SPOPT,PSD), the significance level is defined as the modal covariance matrix term, divided by the maximum modal covariance matrix term. Any term whose significance level is less thanSIGNIFis considered insignificant and is not contributed to the mode combinations. The higher theSIGNIFthreshold, the fewer the number of terms used.SIGNIFdefaults to 0.0001. IfSIGNIFis specified as 0.0, it is taken as 0.0.COMODEFirst
COMODEnumber of modes to be actually combined.COMODEmust always be less than or equal toNMODE(input quantityNMODEon the SPOPT command).COMODEdefaults toNMODE.COMODEperforms a second level of control for the first sequentialCOMODEnumber of modes to be combined. It uses the significance level threshold indicated bySIGNIFand operates only on the significant modes.ForceTypeLabel identifying the forces to be combined:
STATIC
—
Combine the modal static forces (default).
TOTAL
—
Combine the modal static plus inertial forces.