Isotropic-kinematic cyclic hardening characteristics of plate steels

Cyclic hardening of metals is considered as one of the most important features that affects extremely the hysteresis behavior of steel structures. One approach to study this characteristic is dividing it into two components, including isotropic hardening and kinematic hardening, and defining any of these components for any type of metals by calibrated data obtained from experiments. However, the lack of these calibrated data on metals, restricts this approach. Therefore, in this paper the isotropic and kinematic characteristics of five different steel grades from 100 to 485 MPa, under various strain ranges between ±1 and ±7% were proposed. Afterwards, four of these five grades were validated in order to find the appropriate combination of data for any of them, and to compare the result of this approach with those obtained from a well-known hardening model, Ramberg-Osgood. The results showed the high accuracy of the isotropic-kinematic hardening model in comparison to the Ramberg-Osgood method.