Sahil Sura
Ansys Employee

Hi Aitor, 
Yes, the connection is right (06:12 of How To Perform Prestressed Modal Analysis — Lesson 2 - ANSYS Innovation Courses), I would recommend you to go through the video once to gain insights on the pre-stressed modal analyses. 
As mentioned, Modal analysis is a 'Linear' analysis so non-linearities won't get reflected in the same. But to inculcate those, we use a structural analysis as the preceding analysis. So if you focus on the outcomes of the analysis both are different for structural and modal. Thus there will definitely be a difference in support and no loading in Modal analysis. 

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