Seismic performance of wall-beam joints in composite walls with u-shaped energy dissipation devices
Jian Li,Kai Liu,Zhe Zhao,Bo-Kai Chen
Abstract
To address the challenges associated with post-earthquake repair of connections between double-steel plate composite shear walls and H-shaped steel beams, a replaceable joint is proposed that integrates a dual energy dissipation mechanism combining friction and ductility. Two-stage energy dissipation is achieved through slip friction at slotted holes in the web of U-shaped connectors and plastic deformation of their flanges, thereby confining plastic damage effectively to the replaceable unit. This design fulfills the seismic objective of a "strong main structure–weak joint" concept, facilitating rapid post-earthquake replacement and repair. A detailed ABAQUS finite element model of a composite shear wall joint incorporating U-shaped energy dissipation devices has been established based on the dimensions of wall-beam joints commonly used in engineering practice. The effects of the web thickness, flange thickness, discontinuity length of the U-shaped connector, and bolt pre-tightening force on the seismic performance of the joint are investigated. Parametric analyses reveal that increases in the web and flange thicknesses of the U-shaped connectors, reductions in the discontinuity length, and increases in the bolt pre-tightening force enhance the load bearing capacity. However, excessive web thickness reduces ductility, and an increase in flange thickness tends to cause plastic damage to shift to the web. Moreover, when the preload exceeds 100 ken, frictional energy dissipation within the joint is suppressed. Finally, based on the parametric analysis results, a semi-empirical formula is proposed for predicting the load-bearing capacity as a function of geometric dimensions and bolt pre-tightening force, exhibiting a maximum error within 10%.
