The cross response PSD between two items is computed using the equation:

(17–151)

where:

p = reference number of first item (input as IA on RPSD command)

q = reference number of second item (input as IB on RPSD command)

p and q can be displacements, stresses, or reaction forces

denotes the real part of the argument

All other variables are defined in Response Power Spectral Densities and Mean Square Response. When p = q, the above cross response PSD becomes the auto response PSD.