Moment–Rotation Parameters for Composite Shear Tab Connections

Shear tab connections, acting compositely with the floor slab, are capable of providing some lateral resistance in steel frame buildings. This resistance was suspected from the events of the 1994 Northridge Earthquake and verified in a series of tests. For performance evaluation of steel structures, it is necessary to quantify the non-negligible rotational strength and stiffness of these composite connections, a task that cannot be accomplished through the use of simple rules of thumb. Therefore, trends in the moment–rotation behavior of the connections are identified from comparison of the cyclic behavior against parameters such as number of bolts, type of concrete, use of slab reinforcement, and the presence of a column web cavity. Analysis of these trends leads to guidelines for determining parameters for a basic backbone moment–rotation curve. These guidelines depend heavily on applicable limit states for elements of the connections and connection geometry. Predicted values of moment and rotation capacity are compared against experimental values, showing good agreement overall and defining limitations and directions for further development of these procedures.