PSDCOM
PSDCOM, SIGNIF, COMODE, , ForceType
Specifies the power spectral density mode combination
method.
- SIGNIF
- Combine 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 than- SIGNIFis considered insignificant and is not contributed to the mode combinations. The higher the- SIGNIFthreshold, the fewer the number of terms used.- SIGNIFdefaults to 0.0001. If- SIGNIFis specified as 0.0, it is taken as 0.0.
- COMODE
- First - COMODEnumber of modes to be actually combined.- COMODEmust always be less than or equal to- NMODE(input quantity- NMODEon the SPOPT command).- COMODEdefaults to- NMODE.- COMODEperforms a second level of control for the first sequential- COMODEnumber of modes to be combined. It uses the significance level threshold indicated by- SIGNIFand operates only on the significant modes.
- ForceType
- Label identifying the forces to be combined: - STATIC - — - Combine the modal static forces (default). - TOTAL - — - Combine the modal static plus inertial forces.