High strain-rate properties of armor materials
Ang, Jordan Jing Yi
Date of Issue2015
School of Mechanical and Aerospace Engineering
Dynamic behavior of materials have some influence on ballistic performance. To understand the ballistic performance, dynamic behavior has to be studied first. This report makes use of static testing in quasi-static compression test and dynamic testing in SHPB experiments to understand the material properties. From static testing, it proves that with higher hardness of 4340 steel, a higher stress-strain relation is obtained. From dynamic testing, it proves that at higher strain rate, a higher stress-strain relation is obtained. After that, with the understanding of these properties, JC model parameters are determined. Using the method of separation of variables and the least-square method, yield stress, hardening constant, hardening exponent and strain rate constant are found. These parameters are then used in AUTODYN® simulations. The results of these simulations show that with higher hardness of 4340 steel target, the depth of penetration from the tungsten projectile is lower. They also show that with higher initial velocity of the projectile, the depth of penetration is higher. Therefore, a better understand of ballistic performance is known.
Final Year Project (FYP)
Nanyang Technological University