Alternative method for the identification of the strain hardening behaviour along the rolling direction of coil

Abstract

AbstractA new method is proposed for the measurement of the mechanical properties of X70 coil steel along the rolling direction using an inverse procedure and digital image correlation. To characterise the mechanical properties, a tensile test was performed on a curved API sample. To clamp the curved sample without inducing plastic deformation, additional shims were machined compensating the curved clamping region. Using this modified test setup, finite element model updating, and digital image correlation, the mechanical properties were identified without influencing the material behaviour and considering the entire wall thickness. These results were compared with a flattened API tensile specimen. A yield stress reduction was found compared with the identified yield stress on the curved specimen equipped with shims. Additionally, the influence of the residual deflection after flattening on the yield stress has been scrutinised.