Experimental and numerical investigations on novel post-tensioned precast beam-to-column energy-dissipating connections

This paper proposes novel self-centering post-tensioned hybrid connections (PTHC) with energy-dissipating elements, with assembly requiring grouting only once and convenient construction. To investigate the seismic performance of the hybrid connections, cast-in-place beam-to-column and assembled monolithic beam-to-column connection specimens were designed as comparison test specimens. Subsequently, four PTHC specimens with different test variables— restraint conditions of beam end, unbonded lengths of the energy-dissipating elements, energy-dissipating material, and initial prestress were designed and investigated by quasistatic experiments. The test results showed that the designed PTHC specimens had high energy dissipation capacity, good self-centering capacity, high ductility, and low accumulated damage. Concrete restraints at the beam end effectively restrained the buckling behavior of the energy-dissipating elements. Finally, numerical simulation models of the PTHC specimens were established to further investigate the effects of the design parameters on the bearing and energy dissipation capacity. Combined with the test results, the PTHC specimens were found to have good seismic resilience. Balancing the contributions of the energy-dissipating elements and prestress to the load carrying capacity appeared to be critical.