Interface defeat is when a ceramic armour system, typically on an

armoured fighting vehicle An armoured fighting vehicle (British English) or armored fighting vehicle (American English) (AFV) is an armed combat vehicle protected by vehicle armour, armour, generally combining operational mobility with Offensive (military), offensive a ...

, defeats a

kinetic energy penetrator A kinetic energy penetrator (KEP), also known as long-rod penetrator (LRP), is a type of ammunition designed to penetrate vehicle armour using a flechette-like, high- sectional density projectile. Like a bullet or kinetic energy weapon, this ty ...

at the ceramic's front surface. Above a certain impact

velocity Velocity is a measurement of speed in a certain direction of motion. It is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of physical objects. Velocity is a vector (geometry), vector Physical q ...

, known as the ''transition velocity'', interface defeat can no longer occur and either penetration or perforation of the ceramic occurs.

References

* {{DEFAULTSORT:Interface Defeat Ballistics Vehicle armour