qdval

SpectrumOptions.qdval(tblno1='', tblno2='', sv1='', sv2='', sv3='', sv4='', sv5='', sv6='', sv7='', **kwargs)

Defines PSD quadspectral values.

Mechanical APDL Command: QDVAL

Parameters:

tblno1str

First input PSD table number associated with this spectrum.

tblno2str

Second input PSD table number associated with this spectrum.

sv1str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv2str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv3str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv4str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv5str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv6str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

sv7str

PSD quadspectral values corresponding to the frequency points ( psdfrq ).

Notes

Defines PSD quadspectral values to be associated with the previously defined frequency points. Repeat qdval command with the same table number for additional points. Unlike autospectra ( psdval ), the quadspectra can be positive or negative. The quadspectral curve segment where there is a sign change is interpolated linearly (the rest of the curve segments use log-log interpolation). For better accuracy, choose as small a curve segment as possible wherever a sign change occurs.

Two table numbers are required since values are off-diagonal terms. This command is valid for spopt,PSD only.

This command is also valid in PREP7.