Study on hysteretic performance of welded T-joints circular tube on platform considering seawater corrosion

In this study, the macroscopic hysteretic mechanical behaviour of welded circular tube T-joints corroded by seawater was evaluated through hysteretic mechanical performance tests. Full immersion accelerated electro-chemical corrosion tests with a proportioned seawater medium were conducted on steel specimens obtained from tube joints. The generalised degradation rule of the mechanical performance of the material with the develop-ment of corrosion was obtained via a monotonic tensile test of steel specimens. The hysteresis test of corroded joints revealed that corrosion and cyclic loading have degradation effects on joint strength, stiffness, bearing capacity, and energy dissipation. At a low number of cycles, the effect of corrosion is generally greater than that of cyclic loading. A hysteretic skeleton model that can determine the ultimate load of the corroded joint was established based on the load-displacement curve. Moreover, the hysteretic rules that describe the degradation characteristics of the loading and unloading stiffness were established. Finally, the hysteresis model of corrosion joints was proposed. The model was validated using experimental results, and we demonstrated that it can accurately reflect the effect of the degree of corrosion and loading process on the hysteretic characteristics of joints.