RELATION BETWEEN MATERIAL PROPERTY AND DWELL-TO-PENETRATION TRANSITION VELOCITY FOR SIC CERAMICS

摘要

For SiC ceramic armours impacted by long rod projectiles, increasing the dwell-topenetration transition velocity of the ceramics can significantly improve its ballistic performance. An analytical model is derived to investigate how the transition velocity together with the transition stress are affected by the ceramic property, prestress, and the presence of a buffer. The transition stress is determined from initiation of SiC failure beneath the impact surface meanwhile SiC failure analysis is based on Hertz contact theory and pressure-dependent SiC strength. The relationship between the transition velocity and the transition stress for two types of contact stress distribution, i.e. uniform pressure and Hertz pressure, is derived from the Tate analysis. The predicted analytical model when compared against the experimental data from literature predicts transition velocities and stresses which are consistent. It is applied to analyse how the dwell-to-penetration transition velocity is increased by applying of radial prestress to the ceramic or placing of a buffer on the impact surface of the ceramic.