Seismic performance of a multi-story composite frame with partial shear interaction and partial strength joints

This study investigates the influence of partial shear interaction and partial strength beam-to-column joints on the seismic performance of a multi-story composite frame. The moment-rotation relationship of the beam-to-column joints and the force-slip curve of the beam-to-slab connections have been calibrated on the basis of available experimental tests. The results of the numerical investigations show that the energy dissipation of the composite frame increases by reducing the shear connection degree. The shear connection degree has a significant effect on the total dissipated energy in case of rigid joints, whereas in case of partial strength joints the contribution of the joints to the dissipated energy is predominant. Low shear connection degrees can provide a source of dissipated hysteretic energy, above all in case of rigid joints, and can reduce the ductility demand on other parts of a composite frame, such as partial strength beam-to-column joints. However, the shear connection degree should be high enough in order to protect shear connectors from failure.