Mechanical properties and constitutive models of foamed steels under monotonic and cyclic loading

Foamed steel applications in civil engineering are at their beginning stage. Compared to foamed aluminum, advantages of using steel as a base metal are distinct (e.g., higher strength and modulus). In order to investigate the mechanical properties of foamed steels and to obtain representative material constitutive parameters for finite element analysis, fourteen specimens were tested under monotonic and eleven different cyclic loading schemes in this study. The monotonic and cyclic tensile-to-yield ratios were 2.17 and 1.90 ± 0.17, respectively, and the energy dissipation coefficient ranged from 2.70 to 3.35. The cyclic hardening behavior of foamed steels comprised isotropic and kinematic hardening characteristics, and the isotropic part played the dominate role. Based on the test results, the corresponding material parameters for two cyclic constitutive models, including the Chaboche model and the Giuffré-Menegotto-Pinto model were obtained. Then, the accuracy of the parameters was verified by nonlinear analysis results in ABAQUS and OpenSEES. This work may provide a valuable reference for further research into the cyclic characteristics of foamed steels.