摘   要：异形钢管再生混凝土结构抗震性能优异，且可消纳建筑垃圾、适配现代工程需求，而现有相关研究多集中于常规截面混凝土构件，针对外包钢套加固震损异形钢管再生混凝土柱-钢梁节点的恢复力模型研究较少，对应的抗震理论体系尚不健全。为此，本文设计了3个T形钢管再生混凝土柱-钢梁节点试件，通过试验和有限元模拟方法研究了损伤程度和加固方式对其承载力的影响，并基于试验数据，通过拟合法，考虑定点指向、软化点与刚度退化，构建了相应的恢复力模型。结果表明：外包钢套加固可显著提升震损节点的承载力，使重损节点的承载力基本恢复至无损水平；通过适当折减材料性能来模拟地震损伤的数值方法可靠性良好，有限元滞回曲线与试验滞回曲线吻合较好；恢复力模型拟合结果与试验实测结果、有限元模拟结果的吻合度较高，说明该恢复力模型可用于外包钢套加固震损T形钢管再生混凝土柱-钢梁节点的地震反应分析。研究成果可为类似节点的抗震研究与加固修复提供参考。

Abstract: Structures composed of special-shaped steel tube recycled aggregate concrete exhibit excellent seismic performance, and they can recycle construction waste, which satisfies the requirements of modern engineering. However, existing research mostly focuses on concrete members with regular cross-sections. Few studies address the restoring force model of seismic-damaged special-shaped steel tube recycled aggregate concrete column-to-steel beam joint strengthened with enveloped steel jacket, and the corresponding theoretical system for seismic resistance remains incomplete. For this purpose, three specimens of T-shaped steel tube recycled aggregate concrete column-to-steel beam joints were designed in this paper. Experimental tests and finite element simulations were carried out to investigate the influences of damage degree and reinforcement scheme on the bearing capacity of the joints. On the basis of test data, a corresponding restoring force model was established by the fitting method, taking the pinching effect, softening point and stiffness degradation into consideration. The results demonstrate that strengthened with enveloped steel jackets can markedly improve the bearing capacity of seismic-damaged joints, and the bearing capacity of severely damaged joints can be basically restored to the level of intact specimens. The numerical simulation method that simulates seismic damage by appropriately reducing material properties possesses favorable reliability, and the hysteretic curves obtained from finite element analysis agree well with those measured in tests. The fitting results of the proposed restoring force model show high consistency with both experimental results and finite element simulation results, which verifies that the established restoring force model can be applied to seismic response analysis of seismic-damaged T-shaped steel tube recycled aggregate concrete column-to-steel beam joints strengthened with enveloped steel jackets. The findings can provide a reference for seismic research, reinforcement and repair of similar joints.