Development and investigation of a novel precast beam-column friction hinge joint enhanced with Cu–Al–Mn SMA-plate-based self-centring buckling-restrained devices

Abstract

To improve seismic capabilities and to reduce post-earthquake residual deformation of precast concrete frames, a novel self-centring hybrid connection (SCHC) composed of a rotational friction hinge device (RFHD) and four self-centring buckling-restrained dampers (SC-BRDs) was proposed and investigated for the dry type precast concrete beam-column joints in this study. The configuration and working principles of the SCHC were first illustrated. The effects of solution heat treatment procedures, strain amplitudes, and cycle numbers on the uniaxial cyclic behaviour of prepared Cu–Al–Mn SMA plates were also tested for the SCHC application. Finite element models of the RFHD, SC-BRD, and novel SCHC were subsequently established and preliminarily verified, followed by parametric analyses on several crucial design parameters of the SCHC to optimize its mechanical performance. Results shown that the self-centring ability and strength degradation resistance of the prepared Cu–Al–Mn SMA plates can be significantly improved by subjecting appropriate solution heat treatment procedures. The SMA core element thickness, initial post-tensioning force of high-strength bolt, and distance between SMA and rotation centre are suggested to be designed within the range of 8 mm–10 mm, 565 kN–705 kN, and 120 mm–130 mm, respectively, to achieve appropriate energy dissipation and self-centring performance of the proposed SCHC. The RFHD and SC-BRD can be conveniently replaced after damage in earthquake, which is conducive for rapid repair of the prefabricated concrete structures. Overall, the proposed SCHC shows excellent seismic mitigation ability, self-centring capability, and repairability. The proposed SCHC can provide a reference for the application of some important prefabricated concrete structures in requirement of uninterruptible or rapidly restorable building functions after high seismic effects.