Why are the maximum ANSYS 8.1 PSD SEQV values 2-3 time higher than
a competitor's?

It doesn't seem to be an issue with how SEQV is computed from the 1 sigma values,
because the component shear stress is very high also - around 9000 psi - so an
SEQV value of 19000 is reasonable.

Here is how you can hand calculate the variance of a mode per Theory
Manual Eqn 17-148:

Q=Eff Mass x Integral{H(W)^2 x Input spectrum x 386.4^2}

H is the transfer function between a sinusoidal excitation W
and the natural frequency w.

H(W)= 1/(w^2 - W^2 + i(2x wW)

For the first mode, w = 1929 and H^2 times Input Spectrum
can be integrated numerically. For example, at 300 Hz (1885 rads/sec),
the transfer function is H(W) = 1/(1929^2 - 1885^2 + 2x.02x1929x1885) = 3.19e-6

The contribution of this mode to the 1 sigma value is the square root of the variance
(neglecting modal cross-terms.)

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