Experimental and Numerical Evaluation of Dynamic Response of Novel Armor Grade Steel
摘要
Designing steel structures for ballistic applications requires a thorough understanding of the material behavior under high deformations, temperatures and high strains. Cold worked, annealed and heat-treated steels exhibit different behaviors under impact loading. In the present work, a newly developed cold rolled armor grade steel is mechanically characterized to depict its dynamic behavior using Johnson–Cook (JC) material model. The material flow behavior was modeled and predicted using the JC material and damage models. The experimental determination of JC flow stress parameters was carried out through tests conducted at varying strain rates (10−3–4673 s−1) using split Hopkinson tensile bar (SHTB) and high temperatures (25-600 °C) using special arrangements. Using finite element simulation in conjunction with observations on flat tensile specimens, the damage parameters of the JC failure model were established. Finite element calculations were performed on notched specimens with varying radii (4–18 mm) loaded under uniaxial stress using obtained JC material parameters. Fair agreement was observed between the experimental and numerical data for the newly developed armor grade steel. JC parameters and mechanical properties of the cold rolled armor grade steel were compared with values obtained through previous work on annealed and heat-treated armor grade steel samples. Cold rolled armor grade steel exhibited significant increase in strength and hardness along with substantial decrease in failure strain when compared with annealed and heat-treated steel samples, making it more suitable for ballistic application.