隔板贯通变截面方钢管轻骨料混凝土边柱-箱梁节点抗震性能试验

Seismic performance tests of diaphragm-through exterior joints of lightweight aggregate concrete-filled square steel tubular column with variable sections and steel box beam

对折线隔板贯通变截面方钢管轻骨料混凝土边柱-钢箱梁节点和基本型节点进行了循环加载试验,获得了节点的破坏模式、滞回曲线、塑性转角、耗能能力、节点域应变演化等抗震性能指标.结果显示,上隔板与小截面柱间焊缝的剪应变远大于下隔板与大截面柱间焊缝;基本型节点在几何突变剧烈的梁翼缘对接焊缝侧边、梁腹板角焊缝端点及构造复杂的梁腹板焊接工艺孔处脆断;折线隔板节点的典型破坏模式为折线隔板段形成塑性铰、极限加载时焊接工艺孔处梁腹板屈曲和开裂、塑性铰区隔板断裂、梁腹板竖向角焊缝开裂.折线隔板节点的极限承载力、塑性转角和耗能能力较基本型节点分别增加40.2%~58.6%、22.7%~44.6%和65.7%~118.6%.

Low cycle loading tests were carried out on linear enlarged diaphragm-through exterior joints of lightweight aggregate concrete-filled square steel tubular column with variable sections and steel box beam and basic joint. Seismic performance indexes, such as failure mode, hysteresis loops, plastic rotation, energy dissipation, strain evolution of panel zone are obtained. Test results show that the shear strain of weld between upper diaphragm and column with small section is much larger than that of bottom diaphragm and column with large section. The basic joint fractures brittlely at edges of butt weld of beam flanges where the geometry changes sharply, the end of fillet weld of beam webs and column walls and the welding process holes of beam webs with complex geometric construction. Typical failure modes of joints with linear enlarged diaphragms are plastic hinges formed in linear enlarged diaphragms, buckling and crack of beam webs near welding process hole at ultimate loading, fracture of liner enlarged diaphragms at plastic hinges zone and fillet welds between beam webs and column walls. The bearing capacity, plastic rotation and energy dissipation of the joints with linear diaphragms are increased by 40.2%~58.6%、22.7%~44.6% and 65.7%~118.6% compared with those of the basic joint, respectively.