I think there is a very good reason why structural engineers never see this type of thing, and it's because most structural engineers don't like math. They like clicking buttons in their CAD/FEA/BIM/<insert-latest-TLA> computer system.

The people who write those systems on the other hand enjoy this math very much, and tend to use Galerkin as a verb and will casually point out just how wonderful the Lax-Milgram theorem is.