基于SMA抗剪连接件的半刚接钢框架内填带缝RC墙结构抗震性能及性态设计研究

In composite partially-restrained steel frame-reinforced concrete infill wall (PSRCW) structural system, the shear connectors are easy to occur fatigue failure, which will influence the seismic behavior and the failure modes of PSRCW structure. Aiming at this problem, a new kind of shear connector, made from shape memory alloy (SMA), is introduced into PSRCW structure. Besides, it is good for increasing the ductility of the structure to set up some slits on the reinforced concrete wall. Thus, a new structural system named SMA-PSRCW (with slit) system is proposed in this project. The seismic performance of this structural system is systematically studied through experiments, numerical simulation and theoretical analysis. First, the performance of SMA shear connector will be investigated, based on which the calculation formula about static strength and fatigue strength and the shear hysteresis model will be established. Then the failure mechanism and the transferring mechanism of the force between the components of SMA-PSRCW (with slit) system subjected to earthquakes will be discussed and the ideal failure mode will be proposed. Based on the studies mentioned above, the simplified calculation methods of bearing capacity and stiffness of SMA-PSRCW (with slit) system will be developed and a macro finite element method of this structural system will be built. At last, studies on the performance-based seismic design theory will be carried out for SMA-PSRCW (with slit) system and then a seismic design approach based on the damage state of the structure will be established. Carrying out his project can provide a new way to solve the safety problem of the whole life of structure and mitigate the influence of disaster. Meanwhile, it also can promote the development of new-type structural system, which has the scientific significance and practical utility for preventing serious accidents and ensuring the structural safety.

针对半刚接钢框架内填RC墙（PSRCW）结构中抗剪连接件易发生疲劳断裂，从而影响结构的抗震性能及破坏模式的问题，将形状记忆合金（SMA）制成抗剪连接件引入到PSRCW结构，并考虑内填墙上设缝可提高结构延性，提出SMA-PSRCW（带缝）结构体系。采用试验研究、数值模拟和理论分析相结合的方法研究该结构体系的抗震性能：首先研究SMA连接件的性能，建立其静力和疲劳强度计算公式及抗剪滞回模型；接着探讨SMA-PSRCW（带缝）结构在地震作用下的破坏机理及各部件之间的传力机制，提出该结构理想的破坏模式；进而建立结构承载力和抗侧刚度的简化计算方法，构建结构的宏观有限元模型；最后对该结构开展基于性态的设计理论研究，提出基于损伤的性态设计方法。本项目为解决工程结构在整个寿命期的安全及减小灾害影响提供了崭新的思路，可促进新型结构体系的研究与发展，对减少重大事故、保障工程结构安全具有重要的科学意义和实用价值。

利用形状记忆合金（SMA）良好的物理、力学性能，将其制成抗剪连接件并引入到半刚接钢框架内填 RC 墙（PSRCW）结构中，以提高抗剪连接件疲劳断裂性能，从而改善结构的抗震性能。本项目从元件-构件-结构三个层次逐步开展研究工作。首先通过推出试验研究了多种影响因素下SMA抗剪连接件的力学性能，分析了试件的受力过程和破坏机理；在此基础上，建立了SMA抗剪连接件极限承载力的计算公式和粘结滑移关系式，为SMA抗剪连接件在组合结构中的应用奠定了基础；接着对SMA-PSRCW结构进行抗震性能试验研究，探讨了该结构的受力过程和破坏机理，分析了不同影响因素下该结构的整体和局部抗震性能，并结合进一步的数值分析，探索了结构各部件合理的刚度和强度分配；然后，采用复指数法和ARMA时间序列法对结构的模态参数进行识别，并对比了两类参数识别方法的精度；此外，还研究了结构损伤识别方法，采用短时傅里叶变换进行结构损伤识别，给出了损伤识别流程，并验证了损伤识别方法的有效性。上述工作为SMA新型元件的在土木工程结构中的应用提供了科学支持和依据，也为解决工程结构在整个寿命期的安全和减少灾害影响提供了崭新的思路，可促进新型结构体系的发展。