Hi,

I want to apply two different acceleration PSD curve in two different positions for random vibration analysis. That means I need secondary base motion function in random vibration analysis, abaqus only support *Base Motion keyword.

But Abaqus learning material (material name: Linear Dynamics with Abaqus) said "User can independently define a big mass and force excitation".

I have the information about 'big mass' and accelerate PSD curve only. So my question is how many force PSD should I apply?

Thx!