Mostly just Balken, with various adjectives tacked onto it to describe its function

Deckenbalken, Bundbalken, Ankorbalken, Kehlbalken, etc.

The closest sounding thing I can think of in terms of sound to 'Dragonbeam' would be 'Tragbalken' which is a beam that runs under another to carry it, like a floor support beams upon which the joists are lodged.