why can’t kevlar stop rifle bullets even though it’s strong than steel on an equal weight basis?

Question

Ar500 steel plate can stop rifle bullets. In my brain I’m thinking like “well if kevlar is stronger than steel, then slab of kevlar of the same size of an ar500 plate should stop rifle bullets too”. Clearly it doesn’t and I don’t understand why

In: Engineering

Answer 1

Kevlar is made of fibers, rifle rounds are able to lodge themselves between the fibers stretching them until they pass through

This is why hard armor has plates such as steel or cemeric while soft armor, made for handguns) doesn’t

This is also why it can be bulletproof but not stab proof