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 considered soft armor. It’s light, thin, and easy to wear. We wear plate carriers for larger calibers. These just hold steel or ceramic plates. 10 pounds of Kevlar is better at stopping something than than 10 pounds of steel but steels a lot heavier and we can wear more steel plates than we can wear kevlar.