Resizing surrounding environment of an object

Hello everybody, I am working on CATIA and SIMULIA from the 3DExperience platform.

I have an object that is a part of a bigger assembly. This object is fixed on a structure with stiffeners and partition walls. My problem is that this structure is 10 meters long on both side of this object and I would like to "resize" the surrounding environment of the object (maximum of 1.5 meters) in order to have a smaller area of study to bring to my SIMULIA module and have then less elements and nodes for my shell modelling, do you have any idea how to achieve that?


Thanks