When dreaming of beating someone up but they are not injured?

Maybe It means that you've been stressing about someone or something. For example, break up? You love he/she so much, but you might hate he/she for leaving or cheating. You don't have to be dreaming of a certain person, because you bottled so much anger inside you that your imagination makes an "imaginary person" in your dreams. If you KNOW who that certain person was then you got your answer.

and about the they are not injured part? It probably means that, that person overcome you or that you really wanna hurt them but you cant in reality.