Is there a tutorial about how to blow things up, or how to stress test? (I haven't read all the docs yet. I'm just curious how hard is to do it. And skimming through the docs I haven't found material related to it.)
The codes that simulate blowing things up and stress testing are not part of BRL-CAD. BRL-CAD is a solid modeling system used for creating and manipulating geometry. Our libraries are used by several *analysis* codes that do what you suggest, but we are strictly a geometry package.
Is there a repository of such analysis code, or do I have to make a custom one?
There are repositories of such analysis codes, but you don't likely have access to them. You'll have to write your own. That is one of the things the BRL-CAD libraries are really good for. There is a document on the main website that describes in detail how to write applications that use BRL-CAD: