钢管混凝土柱-混合梁节点抗震性能试验研究

提出适用于装配式大跨度组合框架结构的钢管混凝土柱-混合梁节点. 为了研究节点的抗震性能及受力机理，对2个足尺中柱节点试件进行低周往复加载试验. 2个试件分别采用混合梁端型钢翼缘削弱式(RBS)节点以及梁端普通型钢节点. 对2个节点的破坏形态、耗能能力、承载能力、延性以及混合梁的应变分布规律进行对比分析. 试验结果表明，对梁端型钢翼缘的削弱处理可以有效促进试件在翼缘削弱区形成塑性铰，避免梁端焊缝的脆性破坏. 相比型钢未经处理的节点，翼缘削弱节点展现出更好的延性和耗能能力；梁底附加钢筋屈服后的黏结滑移会影响节点的耗能能力，在锚固长度满足规范要求的前提下，应适当增加其配筋率，以防止过早出现附加钢筋屈服后的黏结滑移.

Experimental study on seismic performance of joints connecting concrete-filled steel tube columns and hybrid beams

A novel joint was proposed for connecting hybrid load beams and concrete-filled steel tube columns for long-span prefabricated structures. Cyclic reciprocating tests were conducted on two full-scale interior joint specimens to investigate the seismic performance and mechanical performance of the proposed joint. Two joint specimens were designed with different types of hybrid steel-concrete beams, i.e., reduced beam section (RBS) and untreated H-steels were respectively used at the beam ends. The seismic performance of the joints was analyzed comprehensively based on the failure pattern, dissipated energy, bearing capacity, ductility and strain distribution along the precast hybrid beams. Test results showed that the specimen with RBS region can promote plastic hinge formation in the region, and avoid the brittle fracture of beam end welds. In contrast, the proposed joint with RBS region exhibited better ductility and energy dissipation capability than the joint with untreated steel beam. The energy dissipation of the specimens was affected significantly by the bond slip after the anchoring bars entered the yield stage. Therefore, When the anchorage length of the bars satisfies the design recommendations, a sufficient reinforcement ratio of the bars should be ensured to prevent the emergence of the anchorage bar bond slippage after the bars yielded.