Capacity Evaluation of Eight Bolt Extended Endplate Moment Connections Subjected to Column Removal Scenario

Abstract

The extended stiffened endplate (8ES) connection is broadly used in the seismic load-resisting parts of steel structures. This connection is prequalified based on the AISC 358 standard, especially for seismic regions. To study this connection’s behaviors, in the event of accidental loss of a column, the finite element model results were verified against the available experimental data. A parametric study using the finite element method was then carried out to investigate these numerical models’ maximum capacity and effective parameters' effect on their maximum capacity in a column loss scenario. This parametric analysis demonstrated that these connections fail at the large displacement due to the catenary action mode at the rib stiffener's vicinity. The carrying capacity, PEEQ, Von-Mises stress, middle column force-displacement, critical bolt axial load, and the beam axial load curves were discussed. Finally, using the Least Square Method (LSM), a formula is presented to determine the displacement at the maximum capacity of these connections. This formula can be used in this study's presented method to determine the maximum load capacity of the 8ES connections in a column loss scenario.