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

A rifle induces more spin to the projectile than a handgun. Kevlar is a weave of materials and that construction is meant to diffuse the velocity of the projectile and spread the impact laterally. If the projectile is larger and spinning more that cannot be accomplished. Steel is condensed and tempered material that has tightly packed atoms. Steel relies upon density to deflect projectiles.