Influence of SD effect on Johnson–Cook hardening constitutive material model: Numerical and experimental investigation for armor steel

Abstract

The influence of strength–differential (SD) effect has been investigated on Johnson–Cook (JC) material model parameters for armor grade RHA steel. Two set of JC model parameters has been developed with the help of compressive and tensile flow curve. Further, a finite element analysis (FEA) of static (at 10⁻³ s⁻¹) and dynamic indentation (at 10⁴ s⁻¹) has been performed to validate the effect of tensile and compressive JC material model parameters. In addition, static and dynamic indentation FEA results has been compared with the expanding cavity model (ECM) and experimental Split–Hopkinson pressure bar results, respectively. FEA simulation with compressive data has been shown good agreement with experimental results and analytical models. %SD effect is increased with an increase in plastic strain in armor grade RHA steel.

Keywords:

• FEA
• high strain rate
• plastic flow behavior
• SD effect
• static and dynamic indentation
• strain hardening

Acknowledgments

The authors are grateful to Vice Chancellor, DIAT (DU), Pune for permitting to publish this paper in the journal. The authors are also thankful to Director, DMRL, Hyderabad for extending the facilities for conducting experiments. Acknowledgements are also due to the scientists and technical staff from Amor division, DMRL, Hyderabad.