Material Calibration for Static Cyclic Analyses

Abstract

The material behaviour constitutive laws play a central role in the analysis of engineering components. With the focus to improve the representation of stress-strain response under non-monotonic loadings, several models for cyclic plastic deformation have been developed in recent years. Present FE commercial packages provide models for the analysis of plastic deformation of metallic materials, even though the most recent models are yet to be implemented. A combined isotropic/kinematic hardening model can be used as an extension of simple linear models. This approach provides a more accurate approximation to the stress-strain relation than the linear model. It also models other phenomena, such as ratchetting, relaxation of the mean stress and cyclic hardening, which are typical of materials subjected to cyclic loading.
Present paper presents the calibration and validation of the numerical model as part of a research project that was performed to check the validity of the moment frame connections of an 18-story steel structure. The finite element models were calibrated using experimental tests performed on four full-scale specimens at the CEMSIG Laboratory, Politehnica University Timisoara, Romania. Based on experimental test results, multiple cyclic material behavioural models were employed in order to obtain the best fitting curve.