Bullet Proof Material: How Does It Work?

[jobyts]

How do they make it? is it just a stronger material?

Another one: in movies, the hero neutralize bomb by dropping in water. Is it according to physics principles?

 

[tenseiga]

it isn't exactly bullet proof... more like a small but strong trampoline. doesn't try to stop a bullet dead, tries to desipitate the energy around... look up kevlar on wikipedia

 

[Math Jeans]

Exactly, the material is not exactly *strong*. Think of how a bullet works. When it strikes a person, it has a certain amount of kinetic energy, and when that energy is dispersed on a very small area, it will pierce your skin. What bullet proof materials do is allow that kinetic energy to be dispersed over a larger area.

 

[Astronuc]

Bullet proof materials like Kevlar fiber can with stand the forces of impact. They are high strength materials, and the fibers are interwoven and layered with different principal directions. However, bullet proof materials can stop penetration, but the force can still be transmitted in a concentrated area/point, which could prove fatal. So bullet proof vests are supplemented with certain engineered ceramics which distribute the force over a larger area, while at the same time absorbing some of the impact energy by disintegrating, in some cases.

 

[Danger]

Exactly. For military purposes, those 'trauma plates' are made of titanium along with ceramics. Another advantage (for the wearer, not those standing near him) is that the plates can deflect a bullet away as well as dissipate the impact.
Still, you can't count on one to save you; it's a poor second choice to not getting shot in the first place. Catching even a small round like a .45 ACP will feel like getting smacked with a baseball bat. Broken ribs are a common aftereffect. And, as Astro indicated, a blunt force trauma can stop your heart among other nasty things.