Demand and supply of ductility in steel shear connections

Major response characteristics of shear connections are discussed. Interactions of the shear force, bending moment and rotation are discussed. The beam line concept is refined to include the inelastic range of behavior of the beam. The refined inelastic beam lines are recommended to be used in predicting rotational ductility demand of steel connections under service as well as ultimate load conditions. Inelastic responses of a large number of simply supported beams were analyzed and by using the results, a mathematical model was developed to predict rotational ductility demand of the steel shear connections. Some common test procedures which have been used by several investigators in the past to measure strength or stiffness were evaluated. It is shown that these procedures do not properly simulate the actual conditions in a shear connection. A new test procedure is proposed and was used to measure response characteristics of single-plate, tee and double-angle shear connections more realistically than current procedures.