Equivalent stress intensity factor of pre-Northridge connections

The objective was to quantify the variation of stress intensity factor to weld root flaw sizes in steel frame connections. Finite-element analyses were used to study fracture toughness in welded beam-column connections. Investigations of fracture behavior mainly focused on the standard pre-Northridge connection geometry. Finite element analysis was performed using the ANSYS computer program. Stress intensity factor was calculated through a J-integral approach. The parametric study was conducted to quantify elastic fracture demands as a function of beam geometries. Results show that stress intensity factor is not uniform and is the largest in the middle of beam flange. The breadth of beam flange has primary effect on ratio of equivalent stress intensity factors to average. The ratio is nearly linear with the increase of the breadth, and it increases with the increase of breadth of beam flange.