richard_leeds wrote:Its the same as a lump of wood thrown at a thin foil of metal. That is easy to imagine, and the other examples above are the same idea, ie lead bullet through steel sheet, or shrapnel through a helmet.
Don't forget there are also metallurgical factors beyond mere momentum, its not just something hard battering on something soft, I suspect that analogy is probably on valid for very simple things. You also need to factor in heat, shape of object, shape of projectile, and so on.
Here's a good place to start
http://en.wikipedia.org/wiki/Armor-pier ... _and_shell
and here's one that only uses kinetic energy
http://en.wikipedia.org/wiki/Kinetic_energy_penetrator
"The opposite technique to KE-penetrators
uses chemical energy penetrators.
There are two types of these shells in use: high explosive anti-tank (HEAT) and high explosive squash head (HESH).
They have been widely used against armour in the past and still have a role but are less effective against modern composite armour, such as Chobham or Kanchan, as used on main battle tanks today.
The principle of the kinetic energy penetrator is that it uses its kinetic energy, which is a function of mass and velocity, to force its way through armour. If the armor is defeated, the heat and spalling (particle spray) generated by the penetrator going through the armor, and the pressure wave that would develop, would destroy the target.[1]
The modern KE weapon maximizes KE and minimizes the area over which it is delivered by:
being fired with a very high muzzle velocity
concentrating the force in a small impact area while still retaining a relatively large mass
maximizing the mass of whatever (albeit small) volume is occupied by the projectile—that is, using the densest metals practical, which is one of the reasons depleted uranium is often used.
This has led to the current designs which resemble a long metal arrow."
So it seems they do indeed use the densest material they can find.
