Testing Method for Ceramic Armor and Bare Ceramic Tiles

Over the years research on armor ceramics have demonstrated that the projectile−ceramic tile interaction process consists of several stages. The first stage, which starts at the arrival of the nose of the projectile on the strike face of the ceramic tile, is called the dwell phase as the projectile nose does not penetrate the tile but dwells on its surface. The tail of the projectile still has a constant (impact) velocity, whereas its nose is stopped. This leads to dynamic compressive loading of both the ceramic tile and the projectile. When unsupported, the projectile deforms and, depending on its failure strain, starts to fracture. Several test methods for ceramic materials and ceramic-based armor have been developed and used. In this chapter, the depth-of-penetration test method is analyzed. The alternative test method presented in the chapter is a step in that direction as the ceramic tiles can be tested in bare state as well as with a backing. The variation between identical shots is on the order of 10%, enabling relatively small differences between ceramic samples to be quantified. Furthermore, the dissipated kinetic energy of the projectile is measured and an estimation of the dwell time is obtained. The current view on projectile ceramic interaction is also discussed followed by an explanation of the alternative test method proposed in this work. Finally, some test results using the alternative test method are provided and conclusions are drawn.