Progressive collapse assessment of friction damped post-tensioned steel frames based on a simplified model

Post-tensioned energy-dissipating (PTED) connections for steel frames have drawn great research attention on account of their good seismic performance. Few studies focus on the progressive collapse of friction damped post-tensioned (FDPT) frame structures. The progressive collapse of FDPT frames exhibits a complex three-dimensional mechanical behavior that is quite different from that of traditional frame structures. In this work, a simplified 3D PTED connection model was first established and then used to investigate the progressive collapse behavior of FDPT frames. The influences of material strength, initial PT force, friction force, and axial and bending stiffness of beams on the collapse behavior of FDPT were studied. Finally, the dynamic response of FDPT frames was compared with that of traditional frame structures (TF).