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

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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.