近海大气环境下多龄期钢框架柱抗震性能的试验研究

利用人工气候环境加速锈蚀试验技术对8榀钢框架柱和3种不同厚度的钢材试件进行近海大气环境下的加速腐蚀。对不同锈蚀程度的钢材试件进行拉伸试验，获得钢材力学性能（屈服强度、极限强度、伸长率和弹性模量）随失重率增大的退化规律；并对8榀锈蚀钢框架柱进行低周往复加载试验，考察了锈蚀钢框架柱的破坏过程与特征，从滞回曲线、骨架曲线、强度和刚度退化、耗能能力等角度初步探讨了不同轴压比、锈蚀程度及加载路径对钢框架柱抗震性能的影响。结果表明：随锈蚀程度的增大，钢框架柱极限承载力、耗能能力显著降低，强度和刚度退化明显；随轴压比的增大，钢框架柱承载能力退化、延性变差；加载路径对钢框架柱塑性变形发展和滞回耗能有较大影响。研究成果可为进行基于构件的多龄期钢框架地震易损性研究提供试验支持。

Experimental research on seismic behaviors of multi-aged steel frame columns in the offshore atmospheric environment

In order to study the seismic behaviors of corroded steel frame column in the coastal atmosphere, the accelerated corrosion tests on 8 steel frame columns and 3 groups of steel specimens with different thickness were conducted by applying the technique of artificial climate accelerated corrosion. Based on the tensile tests of steel specimens, the degradation characteristics of steel mechanical properties (yield strength, ultimate strength, elongation and elastic modulus) with the increase of weight loss rate were obtained. Low-cycle cyclic loading tests on 8 specimens were also carried out, the failure modes and characteristics of columns were observed, and furthermore, the influences of axial compression ratio, corrosion degree and loading paths on seismic performance of columns were studied preliminarily from the perspectives of hysteretic curves, skeleton curves, strength and stiffness degradation, and energy dissipation. The results showed that the ultimate bearing capacity, energy dissipation capacity, strength and stiffness of columns degraded significantly with the increase of the corrosion degree. With the increase of axial compression ratio, the bearing capacity and ductility decreased. Moreover, loading paths may have an obvious influence on the development of plastic deformation and hysteretic energy dissipation of columns. As a result, the results may provide the experimental support for carrying out the seismic fragility analysis of corroded steel frame structure.