Numerical and analytical study of stainless steel beam-to-column extended end-plate connections

Abstract

Based on a shell finite element modeling protocol developed and verified by the first author in a previous study, a comprehensive investigation on stainless steel extended end-plate beam-to-column connections was carried out. A total of 180 connection configurations were numerically investigated, to establish a thorough understanding of the influence of a wide range of geometrical parameters on the behavior of this connection type commonly-used in earthquake-resistant steel structures. The initial stiffness; ultimate moment; rotation capacity; dissipative energy; ductility index; and failure patterns were compared and discussed. Furthermore, based on the data acquired from this parametric study, a simple analytical method, for predicting the moment-rotation (M-Φ) characteristics of stainless steel extended end-plate connections, was developed and validated. The results demonstrate that stainless steel extended end-plate connections can be designed to have substantial ductility and rotation capacity, more than satisfactory for beam-to-column joints of structures in seismic zones. In particular, connections with end-plate stiffeners displayed superior performance with enhanced ultimate moment and energy dissipation capacity. The recommended analytical method for M-Φ response of the joints is accurate, with an average error of less than 4% for the ultimate resistance and is robust as evidenced by its prediction of M-Φ response for models that were withheld from its initial calibration. The proposed equations provide, for the first time, a powerful analytical tool that can predict the complete moment-rotation curves of unstiffened and stiffened stainless steel extended end-plate joints, using easy-to-obtain geometric and material properties.