折线隔板贯通方钢管轻骨料混凝土柱-H形钢梁异型节点抗震性能试验研究

通过对折线加强隔板贯通方钢管轻骨料混凝土柱-H形钢梁异型节点和基本型异型节点试件进行低周往复加载试验，研究了隔板折线加强构造对节点破坏形态、承载力、塑性转角、滞回性能、骨架曲线、刚度退化和耗能等的影响。试验结果表明：基本型异型节点在刚度较大、几何尺寸变化较大的大截面梁翼缘对接焊缝侧边开裂，节点的塑性转角约为0.028 rad；隔板折线加强异型节点的主要破坏模式为隔板折线加强区形成塑性铰及延性拉断、梁腹板焊接孔开裂及梁翼缘对接焊缝断裂，其塑性转角可达0.034~0.057 rad，承载力和耗能能力较基本型异型节点分别提高16.5%~47.0%和21.2%~144.0%；隔板贯通方钢管轻骨料混凝土柱-H形钢梁异型节点中，大截面梁先于小截面梁破坏，柱壁板间焊缝未发生撕裂破坏，轻骨料混凝土未发生压碎、拉裂、剥离或滑移破坏，节点的抗震性能主要受钢梁和隔板间焊缝破坏（而非轻骨料混凝土）的影响。

Seismic behavior on diaphragm-through irregular joints of lightweight aggregate concrete-filled square steel tubular column and H-section steel beams with linear strengthened junctures

Diaphragm-through irregular joints of lightweight aggregate concrete-filled square steel tubular column and H-section steel beams with linear strengthened junctures and conventional irregular joint were tested under low-cycle reversed loading. The effects of linear strengthened junctures on failure mode, bearing capacity, plastic rotation, hysteresis loops, rigidity degradation and energy dissipation of diaphragm-through irregular joints were comparatively studied. Tests results show that the conventional irregular joint brittle fractures at edges of butt weld of the large-section beam flanges with large rotation rigidity and the sharply changed geometry. The plastic rotation of the conventional irregular joint is about 0.028 rad. The plastic hinge being formed at the linear strengthened junctures and then ductile fracture, cracking at edges of welding holes of beam web and fracture of butt weld of beam flanges are typical failure modes of the irregular joints with linear strengthened junctures. The plastic rotation of the irregular joints with linear strengthened junctures may range from 0.034 to 0.057 rad. The bearing capacity and the energy dissipation capacity of the irregular joints with linear strengthened junctures increase by 16.5%-47.0% and 21.2%-144.0%, respectively, compared with those of the conventional irregular joints. For the diaphragm-through irregular joints, the failures of the large-section beams are earlier than the small-section beams and no tearing failure of welding between column walls occurs. The post-test examination on the specimens does not reveal any lightweight aggregate concrete materials failure, such as, cracking, crushing, separation or slip, in all tested specimens. The seismic behavior of diaphragm-through irregular joints of lightweight aggregate concrete-filled square steel tubular column and H-section steel beams are dominated by the failure of welding between steel beams and diaphragm ribs rather than lightweight aggregate concrete.