Cast Modular Panel Zone Node for Steel Special Moment Frames. II: Experimental Verification and System Evaluation

A companion paper has described the analytical development of a panel zone dissipator modular node (PZ-MN) prototype for use in seismic-resistant steel moment frames. The PZ-MN dissipates energy through stable yielding of its panel zone, an objective accomplished by mitigating the effects of panel zone distortion on the surrounding members. The PZ-MN is configured directly for this purpose through a casting process. This paper presents experimental verification of the PZ-MN prototype. This process relied heavily on interaction with industry partners to create a castable and constructible shape. The PZ-MN prototype was cast at full scale, fabricated and subjected to FEMA-350 qualification testing with and without gravity load. The PZ-MN prototype exhibited remarkable performance, greatly exceeding qualifying drift angles and possessing exceptional hysteretic characteristics. Using models based on these characteristics, frame performance is evaluated. Design guidelines are given on the basis of the analytical and experimental results.