盐雾环境下锈损钢框架梁柱节点抗震性能试验研究

为研究盐雾环境下锈损钢框架梁柱节点抗震性能的退化规律,对7个不同锈蚀龄期焊接梁柱节点试件开展三维形貌扫描和拟静力试验,研究了锈蚀损伤对框架梁柱节点滞回行为、破坏形态、承载性能、转动变形和耗能能力的影响.研究结果表明:锈蚀梁柱节点滞回环形状虽然较为饱满,但是其包络面积、加卸载刚度和循环圈数明显减小;锈蚀梁柱节点破坏模式均...

Experimental study on seismic performance of corroded steel frame beam-column connection under salt spray environment

In order to investigate the degradation laws of seismic performance of corroded steel frame beam-column connections under salt spray environment, 3D morphology scanning tests and quasi-static tests corresponding to seven welded beam-column connections with different corrosion time were conducted, thereby the effects of corrosion damage on the hysteretic behavior, failure mode, bearing capacity, rotational deformation and energy dissipation capacity of frame beam-column connections were studied. The results show that the shape of the hysteresis loop of the corroded beam-column connection is relatively plump, while the loading and unloading stiffness, the envelope area and the number of cycles decrease significantly. The failure mode of all corroded connections could be classified as the buckling-fracture mixed failure mode, but their failure processes are shortened significantly, and there is a difference of failure mode between beam-column connections in different corrosion stages. The bearing area and the thickness of plate gradually decrease with the increase of corrosion degree, limiting the plastic development level at beam end closed to the flange of column, aggravating the local buckling damage behavior at beam flange, which cause the more significant degradation of ultimate bearing capacity. When the corrosion degree at beam flange is 19.2%, the yield moment and ultimate moment decrease by 28.2% and 32.1%, respectively. The pits formed on the beam flange of frame connection increase the local triaxial stress state and plastic strain level of welded region of beam-column connection, accelerating the initiation and propagation of ductile cracks. As a result, the rotational capacity and energy dissipation capacity of the beam-column connection decrease sharply. When the pitting degree is about 2%, the plastic rotation, total rotation and total energy dissipation decrease by 44.1%, 52.8% and 73%, respectively. After corrosion, the plastic hinge for beam-column connection is still located at the beam end, but the lengths of the equivalent plastic hinge and plastic zone decrease with the increasing corrosion degree.