Development of Johnson Cook Model for Zircaloy-4 with Low Oxygen Content

Abstract Strain, temperature, strain rate and the material properties such as strength coefficient, strain hardening exponent and coefficient of strain rate hardening affect the flow stress of a material which in turn affects the formability. In this present study, tensile tests are conducted on Zircaloy-4 at different strain rates(0.01s-1, 0.005s-1, 0.001s-1)andin the temperature range of 298K to 423K. The flow stress behaviour is analysed and the material constants are determined by modelling the flow behaviour using the Johnson-Cook constitutive equation. The predictability of this constitutive model is determined based on the statistical parameters such as correlation coefficient(R), average absolute error (Δ) and standard deviation (s).