Numerical Study on Seismic Performance of High-Strength CFST Frame Structure with Aluminium Alloy Core Assembled Buckling-Restrained Braces

In this paper, a high-strength CFST-steel beam frame structure with aluminium alloy core assembled buckling restrained braces (HSC-SB-ALAB) was proposed and the brief design method for HSC-SB-ALAB were introduced. To study the influence of high-strength materials and ALAB on the seismic performance of the structure, four 10-story CFST-steel beam structures were designed with material strength and ALAB as variables. The numerical models of the four structures were established by OpenSees, and modal analysis, static elastic-plastic analysis, and dynamic time history analysis were carried out for them. The results indicate that high-strength materials and ALAB could significantly reduce the torsional effect of the structure. In the process of HSC-SB-ALAB failure, ALAB first yielded and began to dissipate energy, then the plastic hinge first appeared in some beams, and few plastic hinges appeared in columns until the later stage, which indicated that HSC-SB-ALAB has the expected yield mechanism. Under seismic load, HSC-SB-ALAB had the highest bearing capacity, and its inter-story drift ratio and story shear were the minimum of the four models. At the same time, HSC-SB-ALAB had the least damage and milder stiffness degradation. It was verified that HSC-SB-ALAB improved the seismic performance of CFST-steel beam frame structures, and the effect of high-strength materials was greater than ALAB.