方钢管混凝土柱-H钢梁上环下贯栓焊混合节点抗震性能数值模拟

Numerical simulation on seismic performance of concrete-filled square steel tube column-H-steel beam bolt-welded hybrid joints with upper annular plate and lower through-diaphragm connection

为了解决钢结构中钢梁下翼缘焊缝根部易发生脆性断裂的问题,提出一种兼有外环板和贯通隔板的新型栓焊混合装配方钢管混凝土柱-H钢梁连接节点。采用有限元ABAQUS对其进行数值模拟,研究该节点的传力机理、屈服机制、破坏模态和耗能性能。通过有限元参数分析,深入研究轴压比、宽厚比以及外环板厚度对节点抗震性能的影响。结果表明:节点呈现典型弯曲破坏模式,塑性铰发生在梁上翼缘与外环板连接处,节点屈服始于翼缘塑性铰区,经由翼缘扩展至腹板,继而钢管混凝土柱屈曲,最终上翼缘焊缝断裂破坏,且节点表现出良好的转动性能;增大钢管宽厚比和外环板厚度均可提高节点承载力,建议钢管宽厚比取值为35~45,钢梁翼缘与外环板厚度及钢材强度一致。

To solve brittle fracture at the welding root of the lower steel beam flange in steel structure, a new type of concrete-filled square steel tube column-H-steel beam bolt-welded hybrid joints with upper annular plate and lower through-diaphragm connection was proposed. Finite element ABAQUS was used for numerical simulation to study the force transfer mechanism, yield mechanism, failure mode and energy dissipation performance of this joint. The effects of axial compression ratio, width to thickness ratio and thickness of outer annular plate on the seismic performance of joints were analyzed by finite element parameter analysis. The results show that the joints exhibited a typical bending failure mode. The plastic hinge occurred between the upper flange and the outer annular plate. The joint yielded at the plastic hinge area of the flange extending to the web through the flange, the concrete-filled square steel tube column buckled, and the welding fractured at the upper flange. The joints shows good rotational performance. The bearing capacity could be improved by increasing the width to thickness ratio of steel tube column and thickness of outer annular plate. It is suggested that the width to thickness ratio of steel tube column should be 35~45, and the steel beam flange has the same thickness and steel strength with outer annular plate.