Hysteretic behavior and cyclic constitutive model of corroded structural steel under general atmospheric environment

To study the hysteretic behavior of corroded steel under cyclic loading, corrosion morphology tests, monotonic tensile tests and cyclic loading tests were conducted on 7 groups of accelerated corrosion specimens and 10 groups of natural corrosion specimens. A new corrosion damage parameter Dn for corrosion degree evaluation and mechanical properties prediction and an extracting method based on corrosion morphology were proposed. It was found that corrosion reduced the strength, ductility and hysteretic energy of steel, and the degradation law of monotonic/hysteretic performance with corrosion damage parameter Dn was obtained. By analyzing the degradation laws of material parameters in classical combined hardening model with the corrosion degree and studying the relationship between the material parameters in monotonic and cyclic loading conditions, a plastic constitutive model of corroded steel was established. The simulated stress-strain curves of corroded steel were in good agreement with the experimental data, indicating that the proposed model successfully simulated the monotonic/cyclic loading performance of corroded steel.