Development of a Cast Modular Connector for Seismic-Resistant Steel Moment Frames Part II: Experimental Verification

A companion paper (Development of a Cast Modular Connector for Seismic-Resistant Steel Frames, Part 1: Prototype Development) describes the development of a prototype design for a cast modular connector (MC) for seismic-resistant steel moment frames. The eventual design, termed the MC "Beta"ť prototype design, was developed through a comprehensive analytical program that focused on the monotonic response of isolated connectors. Analyses of the MC Beta prototype design indicate the potential for excellent ductility and energy dissipation characteristics. This paper focuses on the prototyping and experimental verification of the MC Beta prototype. Steel foundry industry partners cast the MC Beta prototype at approximately half-scale. The scaled MC Beta prototype was tested in isolated fashion under monotonic and cyclic loading. The experimental results confirmed the performance of the analytically-based designs. The MC Beta prototype exhibited exceptional performance in terms of stable energy dissipation, far exceeding qualifying rotational ductility capacities. In direct comparisons to a WT (structural tee) section of similar stiffness and strength, the MC Beta prototype possessed greatly enhanced ductility and energy dissipation characteristics. With the MC Beta prototype developed and experimentally verified under isolated conditions, future work involves comprehensive analytical evaluation and full-scale experimental verification of beam-to-column joints containing the MC using accepted testing protocols and developing a design procedure for moment frames using the MC.