Seismic performance of eccentrically braced frames with low-yield welded hollow spheres

Abstract In this study, an eccentrically braced frame with a low-yield welded hollow sphere was proposed. The structural model was established using ABAQUS software and analysed under monotonic and low-cyclic loading. We analysed the seismic performance, energy dissipation capacity, bearing capacity, secant stiffness, initial stiffness, deformation mode of the structure as well as welded hollow sphere and the fracture behaviour of the structure under monotonic and low-cyclic loading. The analysis revealed that the eccentrically braced frame with the low-yield welded hollow sphere exhibited good seismic performance. The deformation of the structure was mainly concentrated at the bottom of the frame column, low-yield welded hollow sphere, and weak points of both ends of the beam. The deformation of the low-yield welded hollow sphere was larger under the tension and pressure of the brace member. The wall thickness of the welded hollow sphere had a considerable influence on the structural performance. For a greater wall thickness of the welded hollow sphere, the bearing capacity, secant stiffness, energy dissipation capacity, and initial stiffness of the structure were greater, while the deformation of the sphere was smaller. Furthermore, equivalent plastic strain analysis demonstrated that the structure fractured most easily at the junction of the welded hollow sphere and supporting member.