Numerical simulation analysis of double yield points assembled buckling-restrained brace with replaceable inner core

Abstract Based on the concept of rapidly repair after earthquake, a new type of double yield points assembled buckling-restrained brace (DYP-ABRB) with replaceable inner core is proposed. The inner core is composed of two I-shaped plates with different lengths, the peripheral component is composed of channel steel and I-shaped plates, and the unbonded layer is the gap between the core and the peripheral component. The constitutive tectonic composition and force transmission of the DYP-ABRB was carried out. The key parameters in the constitutive model of the material used in the core were determined through the material test, and the obtained parameters were input into the finite element software ABAQUS, which can truly simulate the performance of the finite element model of the brace under cyclic loading. On the base of determining the constitutive model parameters of materials, the design method of the model size and the finite element modeling of the brace, numerical simulation analysis of seismic performance was carried out on six DYP-ABRBs with replaceable inner core. The influences of different parameters, such as weakening width of inner cores, material of inner cores, length of inner cores and form of inner cores on the bearing capacity and hysteretic energy dissipation performance of braces were studied. The results show that the DYP-ABRB exhibits obvious two-stage behavior, and has stable and symmetrical hysteretic performance. All peripheral components are basically kept in the elastic state after loading, which shows that the brace has good post-earthquake repairability. After the earthquake, the brace only needs to disassemble the high-strength bolts and extract the core from both ends for replacement, and the peripheral components can still be used continuously, which greatly reduces the construction waste and economic losses, and has a good application prospect.