可恢复功能的盖板削弱型装配式梁柱节点抗震性能及设计理论

The prefabricated steel structure is featured by standardized design, industrial production and assembly construction, etc. To meet the energy saving and environment protection requirements of green buildings, achieve the aim of seismic rehabilitation and promote the development of the steel structure industrialization in China, a new kind of earthquake resilient prefabricated beam-column connection with reduced cover plate is proposed in this project. Considering the influences of strengthening measures of panel zone and setting methods of ruduced section, some research methods are conducted to investigate the load bearing capacity and energy dissipation capacity of the new prefabricated beam-column connection, such as theoretical analysis, numerical simulation and experimental study, etc. A reasonable design theory of the earthquake resilient prefabricated beam-column connection is established, and its restoring force model is also proposed. In addition, the force transmission, failure mechanism, bearing capacity and hysteretic behavior of the prefabricated beam-column composite connection considering the composite effect of the floor slabs are carried out, and the design theory and restoring force model are also established. Finally, numerical simulation analyses and quasi-static cyclic tests are conducted to investigate the seismic behavior of the prefabricated beam-column connection with reduced cover plate before and after reparation, and the repairable capacity of this connection can be evaluated, which can be taken as references for compiling relevant specifications and engineering applications. The result of the project has great significance for improving the seismic behavior and the repairable capacity of the prefabricated steel structure.

装配式钢结构具有设计标准化、生产工厂化、施工装配化等优点。为符合绿色建筑的节能环保要求、震后可快速修复的功能需求，推动我国钢结构建筑产业化发展，本课题提出一种可恢复功能的新型盖板削弱型装配式梁柱节点。通过理论分析、数值模拟及试验研究相结合的手段，研究节点域加强措施及狗骨削弱区设置等对盖板削弱型装配式梁柱节点承载性能和耗能能力的影响规律，建立一套合理适用且可恢复功能的盖板削弱型装配式梁柱节点设计理论及恢复力模型；对考虑楼板组合效应影响的装配式梁柱节点传力模式、破坏机理、承载能力及滞回特性等进行研究，建立盖板削弱型装配式梁柱组合节点设计理论及恢复力模型；最后，通过数值模拟及低周反复荷载试验系统研究盖板削弱型装配式节点修复前和修复后的抗震性能，评价节点震后可修复能力，为编制相关规范及工程应用提供理论和试验依据。课题成果对提高装配式钢结构建筑抗震性能和震后可修复能力具有非常重要的意义。

装配式钢结构具有设计标准化、生产工厂化、施工装配化等优点，已成为建筑钢结构发展的新方向和新趋势；但若装配式梁柱节点构造或设计不合理，则会导致节点区域内的整体破坏，无法实现建筑结构的可快速恢复功能。基于塑性损伤控制及震后可更换的设计思想，本项目提出了一类可实现结构震后功能恢复的翼缘盖板削弱型装配式梁柱节点形式，通过加强悬臂梁段翼缘及削弱翼缘盖板可将塑性铰转移到翼缘盖板处，实现连系螺栓滑移及翼缘盖板塑性变形双重耗能机制，达到震后只需更换连接板和高强螺栓即可恢复结构使用功能的目的。根据连接处螺栓与翼缘盖板的捆绑作用工作机制，提出了螺栓捆绑连接处截面刚度折减系数计算方法；基于与传统梁柱节点抗弯承载能力等效原则，在综合考虑捆绑截面整体抗弯及翼缘盖板失稳的影响后，从翼缘盖板板厚、翼缘连系螺栓数量、中间排螺栓间距三方面进行公式推导，分别建立了震后可恢复功能的翼缘单盖板装配式梁柱节点设计理论和翼缘双盖板装配式梁柱节点设计理论，并辅以大量精细化有限元数值算例验证了设计理论的合理性。通过系列足尺试件的低周往复荷载试验及修复试验，系统研究了环形隔板尺寸、翼缘盖板布设位置、连接板厚度及材质、螺栓直径及间距、狗骨削弱区形式、梁构件刚度不连续等因素对新型可恢复功能装配式梁柱节点的破坏模式、抗震性能及震后可修复性能的影响规律，验证了所提出设计理论的合理性及有效性。可恢复功能盖板削弱型装配式梁柱节点的提出有效解决了建筑结构震后不可修复或难以修复的问题，极大的降低了地震带来的经济损失；相关设计理论的建立为此类新型可恢复功能装配式节点的实际应用提供了强有力的理论及技术支撑。