Dear friends,

I want to generate a substructure, on which i would like to perform a modal analysis. Here is how i am trying to do that:

1. Step --> Substructure generation
2. BC --> Retained nodes
3. Job

afterwards I am trying to add an additional step of frequency analysis, and in Field Output i select substructure. However, Abaqus only performs modal analysis for the entire structure. Why so?

For the sake of simplicity I am in this stage only interested in 

1. Guyan reduction
2. Dynamic condensation.

Thankful for appropriate answers with details