Really depends on what they are made of.
Steel wheels will bend; when that happens depends on the strength of the steel. They can usually be repaired but it's often cheaper to replace them.
Cast rims (aluminum) will bend a little but usually snap when they do. Cast rims are what we have stock on our cars. I've fixed one that I bent when a tyre went flat. It is often cheaper to try to repair these if the bend isn't too bad.
Forged rims (aluminum) don't bend, they snap. My Mille Miglia summer wheels are forged. They are expensive, but light. These can never be repaired.
