考虑近海环境劣化作用的钢框架节点抗震性能试验研究

采用室内加速锈蚀试验模拟近海大气环境对钢框架材性试件与节点试件力学性能的劣化作用.得到节点试件梁柱翼缘与腹板钢材锈蚀率随近海环境作用时间的相关关系，对材性试件进行拉伸破坏试验，统计回归得到屈服强度、极限强度、伸长率与弹性模量4个钢材材性性能指标随锈蚀率的衰变关系.对4个不同锈蚀程度的钢框架节点试件进行变幅加载试验，考察其破坏形态与特征，分析锈蚀对构件滞回性能、骨架曲线与刚度的影响，得到节点构件耗能能力、累积塑性变形能力、刚度等性能指标随锈蚀率的衰变规律.结果表明：近海大气环境作用使得钢框架节点构件产生初始损伤，致使节点构件梁端在位移低周加载下越早发生断裂，延性降低.

Experimental study on seismic behavior of steel frame joints considering degradation of offshore environment

The accelerated corrosion effect of steel frame specimen and node specimen in coastal atmospheric environment was simulated by indoor accelerated corrosion test. The relationship between the corrosion rate of steel webs and the flange of beam-column of joint specimens and the action time of offshore environment was obtained; the tensile test of the material specimen was carried out. Statistical regression was used to obtain the properties of steel, such as yield strength, ultimate strength, elongation and elastic modulus as a function of corrosion rate. Four steel frame joint specimens with different corrosion degrees were subjected to variable amplitude loading tests to investigate the failure modes and characteristics. Then the influence of corrosion on the hysteretic behavior, skeleton curve and stiffness of the component was analyzed. The decay rules of energy dissipation capacity, cumulative plastic deformation capacity and stiffness with corrosion rate were obtained. Results show that the offshore atmospheric environment causes the initial damage of the steel frame joint members, making the fracture of the beam ends of the joint members occur earlier and earlier under low-cycle displacement loading, and the ductility decreases.