配置SMA的预应力自复位混合钢框架抗震性能研究OA北大核心CSTPCD

To enhance the seismic performance of steel frame structures,prestressed self-centring hybrid connections(SCHC)equipped with SMA were introduced into self-centring hybrid steel frames(SCHF).A simplified numerical model to simulate the hysteretic behaviour of the SCHC was developed based on the physical test data.Validated modelling techniques were employed to develop codified frame structures,considering the fracture behaviour of prestressed cables and SMA bolts.The seismic performance of the SCHF was assessed via static pushover analyses,nonlinear dynamic analyses and fragility analyses.The results indicated that the SCHF exhibited trilinear flag-shaped hysteretic features and excellent self-centring performance.Compared to the self-centring steel frames(SCF)equipped with prestressed cables only,the SCHF exhibited better collapse resistance performance and self-centring performance.The collapse margin ratio of the SCHF was increased by 50％,and the maximum damage margin ratio was increased by 55％.Nonlinear spectral analyses were conducted based on the equivalent single-degree-of-freedom systems,confirming the introduction of the complementary mechanism composed of prestressed cables and SMA bolts can effectively reduce the inelastic seismic demand,which revealed the seismic mechanism of the SCHF from the perspective of material-structure integration.