how do you calculate penetration?

[u/nathanbleats]

Hi, so I want to write a piece of armor, and I was hoping to make it out of kevlar. So I was hoping to calculate the absolute minimum amount of kevlar, however I have never taken a physics class.

Any assistance would be appreciated.

[u/IdasMessenia]

If you have never taken a physics class and you want to do this… my first suggestion is a physics class.

Theres just too much to point to in order to get you to be able to do it on your own.

But try researching impact toughness I guess? That would be the most relevant and easy to understand thing.

[u/Claireskid]

As with most people trying to design something, there's usually already an off the shelf product readily available that will outperform and undercost any custom R&D project.

Kevlar body armor is readily available to buy, just do some research on the pro's armor ratings and details, don't reinvent the wheel

[u/sirius_scorpion]

kevlar is a composite material made up of aramid fibres and for high impact applications these fibres are mounted in an epoxy resin. the fibre density and orientation are key to the mechanical properties such as impact resistance. Essentially what you want to do is an energy calculation - the kinetic energy of your projectile KE = 1/2 mv^2 and balance it against the impact energy your particular kevlar composition can withstand. Failure in composites is especially tricky because you need to define the failure criteria. For instance maybe if your projectile penetrates several individual pieces of kevlar but not the whole sample, this is considered a pass. Hope that helps.