# I'm working on a simulation for ballistics

1. May 31, 2008

### tuoni

I'm working on a simulation for ballistics, and I am in dire need of some help with elasticity. It is primarily to be used in bullet penetration. Given the impact velocity $(v := m/s)$, impact energy $(E := J)$, and cross-sectional area $(A := m^{2})$ of a bullet, and the strength(s) of the material $(\xi := Pa)$, are there any simple formulas to approximate the forces $(F := N)$ and stresses $(\sigma := Pa)$ acting on the material?

It is not meant to be accurate, but the approximations still need to be realistic. It is much easier to work with formulas and physics if it is realistic, even if only crude approximations!

There are five different forms of deformation:
• Compression
• Tension
• Shearing
• Torsion
• Deflection (bending)

There are three different states:
• Elastic -> temporary deformation
• Plastic -> permanent deformation, temporary failure
• Failure -> permanent failure

There are two different strengths:
• Yield strength (elastic -> plastic)
• Ultimate strength (plastic -> failure)

[EDIT] Hardness should probably be in there somewhere too. Any help is appreciated, even if only some comment of link with possible formulas, etc.

Last edited: May 31, 2008