Morning, /k/.

I've been doing your average puke undergrad final paper for introductory physics. My professor, being the unorthodox sort, gave me leave to pursue a subject I was interested in as opposed to one of the traditional prompts. So, I'm tasked with explaining the physics involved with SAPI plates. I find myself, however, at a loss for sources actually documenting the physics involved with such a phenomena- many places -mention- them, insofar as "they stop bullets by expending their energy into breaking the plate", but I haven't really come across much hard science.

Before I gave up and just decided to do a paper on duel-prop helicopters instead, I figured I'd take one last gamble and come to the experts here to see if they had any usable sources that mentioned some hard science as opposed to recycling the same quote to sound like an operator.