Impact response of ceramic structures - A review

A review of the ballistic performance of ceramics like alumina, silicon carbide and boron carbide as well as toughened ceramic like zirconia toughened alumina is presented herein. Based on the backing provided, ceramic armors are subcategorized into monolithic (no backing), ceramic-metal, ceramic-composite, multi-layered and hybrid. In each of these categories, the ceramic plays the similar role of absorbing the initial kinetic energy of the projectile. The backing layer absorbs the remaining part of the energy to stop projectile from penetrating. Ceramic in pure form is hard but a brittle material whose fracture toughness can be increased by using some toughening methods which are discussed in this article. This study mainly focuses on the analytical, experimental and numerical studies that have been performed by different authors on ballistic study of ceramic/ceramic armors. The analytical models have been used to predict the residual and ballistic limit velocity of the projectile. Few studies have shown decent performance in comparison to the experimental results. Experimental studies consist of different configurations of ceramic/backing with likes of alumina, silicon carbide and boron carbide backed using metals and composite fibres. Considering the mechanical properties, boron carbide is the best material but silicon carbide also provides similar performance under some conditions. Numerical simulation studies have been performed using finite element codes like ANSYS, LS-DYNA, ABAQUS and AUTODYN for analysing the impact response of ceramic materials and Johnson-Holmquist material model is preferred to predict the response of brittle materials like ceramics. The mechanical properties of ceramics like hardness, fracture toughness, modulus of elasticity etc. all play a vital role in the behaviour of ceramics when subjected to projectile impact at high velocity. The present work reviews the studies conducted on different ceramic materials at various impact velocities of projectiles and energy levels to throw more light on projectile impact behavior on ceramics.