1
general::
Phrase(s): bang something up
to crash or wreck something; to damage something. • Don’t bang my best skillet up! • Who banged up my best skillet?, Phrase(s): bang someone up
to beat someone up; to assault someone; to damage someone. • The crooks banged him up a little bit. • The crash banged up the passengers in the car. • She banged herself up badly.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Damage, injure, as in Banging up the car a second time will make Dad very unhappy, or Mother fell down the stairs and was all banged up. The verb to bang alone had this meaning from the 1500s on, up being added in the late 1800s. In the early 1800s it gave rise to the colloquial adjective bang-up, for excellent or very successful, as in David did a bang-up job baking the birthday cake.
American Heritage Idioms