Investigation on the Weld Damage Behavior of Steel Beam-to-column Connection

A large number of steel moment frames fractured at the welds of beam-to-column connections in earthquake. As the weld damage behavior is a crucial factor for aseismic performance of steel frame connections, 20 local welded connections representing beam-to-column connections were tested under monotonic and cyclic loads to study the weld damage behavior in this paper. The failure modes and deformation curves were recorded; the effects of material strength, load types, and beam geometries on the connection damage behavior were analyzed. Three damage evolution models were calibrated, the relation between weld damage and macro connection performance was established. The results indicate weld cracking and plate buckling are the main causes of the connection damage; the range of cyclic loads is the key factor affecting the weld damage level; the plastic strain based damage model illustrate the damage process with good accuracy. This study provide technical basis for the damage evaluation and fracture prevention of the welded steel beam-to-column connections.