Cast Modular Panel Zone Node for Steel Special Moment Frames. I: Analytical Development

A panel zone dissipator modular node (PZ-MN) has been developed for use in seismic-resistant steel moment frames. The PZ-MN is configured directly for optimal seismic performance through a casting process. The PZ-MN dissipates energy through stable yielding of the panel zone. This objective is accomplished by mitigating the effects of panel zone distortion on surrounding members and connections. Field welds are removed from critical cross sections and demands are redirected in noncritical paths. A cast piece easily accommodates the geometries and features to meet this objective. The PZ-MN was developed through a comprehensive analytical research program and verified through full-scale experimentation. This paper describes the analytical development stage. Investigation of trial configurations, key parameters, and enhancements resulted in a prototype design for the PZ-MN. The PZ-MN prototype shows the potential for excellent seismic performance, including under the combined effects of lateral and gravity load. This performance is experimentally verified in a companion paper.