Performance-based seismic design of innovative self-centering connection with modified top and seat angle

近年来，人们进行了广泛的研究，以开发具有最小地震损伤和残余变形的自定心结构。预制混凝土结构首次引入SC结构。随后，同样的概念被应用于钢弯矩框架结构。在SC连接中，无粘结后张拉（PT）股或杆用于连接结构梁和柱。由于摇摆机制，在梁柱界面处的间隙开闭提供了侧向载荷下的大量变形能力。结合附加能量耗散元素（如顶座角），得到具有旗形迟滞特性的混合动力系统。采用这种连接方式的结构在横向荷载作用下摇摆，然后恢复到原来的位置。先前的研究表明，由于较短的角度长度、不足的角度厚度或较低的材料强度，对顶部和阀座角度的实验研究不足可能会导致SC连接中的意外行为。此外，还没有SC连接中修改顶座角的实验数据。提出的研究项目将通过试验和数值研究，利用钢抗弯矩框架中改进的顶座角自定心连接的概念来克服上述缺点。拟议的研究将与TKI建设合作进行。TKI参与了由钢、混凝土和木结构组成的工业、住宅和商业建筑的建设。TKI看到了在低陆平原和不列颠哥伦比亚省北部扩展业务的绝佳机会，在这些地区，地震危险是设计和细节设计的重要考虑因素。TKI认为由结构钢制成的预制结构是一种可行的替代方案，因为与其他结构系统相比，这种系统将提供更好的质量控制和改进的项目管理。该项目的成功完成将使TKI和其他加拿大公司在预制自定心钢结构建筑方面具有更好的抗震性能。

Extensive research has been conducted in past years to develop self-centering (SC) structures with minimal seismic damages and residual deformations. SC structures were first introduced for precast concrete structures. Subsequently, the same concept was applied to steel moment frame structures. In SC connections, unbonded post-tensioned (PT) strands or bars are used to connect the structural beams to columns. Gap opening and closing at the beam-column interface, as a result of the rocking mechanism, provides substantial deformation capacity under lateral loading. When combined with supplemental energy dissipation elements (e.g., top-and-seat angle), a hybrid system with a characteristic flag-shape hysteresis behavior is obtained. Structures using this type of connection sway under lateral load and return to their original positions afterward. Previous research has shown that inadequate experimental research on top-and-seat angles may lead to unexpected behavior in an SC connection due to shorter angle length, insufficient angle thickness, or lower strength of the material. Moreover, there is no experimental data on modified top-and-seat angle in SC connections. The proposed research project will utilize the concept of modified top-and-seat angle-based self-centering (SC) connections in steel moment resisting frames through experimental and numerical studies to overcome the above-mentioned shortcomings. The proposed research will be performed in collaboration with TKI Construction. TKI has been involved in the construction of industrial, residential and commercial buildings made of steel, concrete and timber structures. TKI sees a great opportunity to expand their businesses in the Lower Mainland and Northern British Columbia where seismic hazard is an importation consideration for design and detailing. TKI considers prefabricated structures made of structural steel as a viable alternative since such systems will give them better quality control and improved project management compared to the other structural systems. Successful completion of this project will give TKI and other Canadian companies an edge in prefabricated self-centering steel buildings with improved seismic performance.