Abstract
The analysis of the ductility and cumulative plastic deformation (CPD) demand of a high-performance buckling-restrained brace (HPBRB) under a strong earthquake and its aftershocks is conducted in this paper. A combination of three continuous excitations with the same ground motion is used to simulate the affection of a strong earthquake and its aftershocks. A six-story HPBRB frame (HPBRBF) is taken as an example to conduct the incremental dynamic analysis (IDA). The seismic responses of the HPBRBF under one, two, and three constant continuous ground motions are compared. The IDA result indicates that the ductility and CPD demand of the BRBs under the three constant continuous ground motions are significantly larger than that excited by only one. Probabilistic seismic demand analysis (PSDA) is performed using seven near-fault ground motions and seven far-fault ground motions to consider the indeterminacy of ground motion. The probabilistic seismic demand curves (PSDCs) for the ductility and CPD demand for the HPBRB under the strong earthquake and its aftershocks are obtained in combining the probabilistic seismic hazard analysis. The results indicate that the AISC threshold value of the CPD with 200 is excessively low for a HPBRBF which suffers the continuous strong aftershocks with near-fault excitations, and a stricter threshold value should be suggested to ensure the ductility and plastic deformation capacity demand of the HPBRB.
Highlights
A buckling-restrained brace (BRB; Figure 1) is a type of metal-yield energy dissipation device, which can be fabricated in a frame structure as a brace to provide lateral stiffness during the lifetime of the structure
According to the theory proposed by the PEER, the seismic response of a structure is described as the engineering demand parameter (EDP), and the peak ground acceleration (PGA) of the ground motion is chosen as the intensity measure (IM) in this paper, while the considered period of time is determined as 50 years according to the design reference period of the common engineering structures in China
As the strain of the BRB should be calculated as the ratio between the deformation and the length of the yielding segment, the simplified numerical model of BRB in this study assumed that the full length of the member is arranged as the yielding segment, and the result of the analysis model should be multiplied by 2 in the postprocessing process to obtain the ductility and the cumulative plastic deformation (CPD) of the high-performance buckling-restrained brace (HPBRB) in the actual structure
Summary
A buckling-restrained brace (BRB; Figure 1) is a type of metal-yield energy dissipation device, which can be fabricated in a frame structure as a brace to provide lateral stiffness during the lifetime of the structure. Researchers have performed extensive studies on the BRB frame (BRBF) to measure the demand of the energy dissipation capacity of the BRB, and studies on the low-cycle fatigue property of BRBs in a single ground motion have been relatively fully developed. Usami et al [11] proposed the high-performance BRB (HPBRB), in which the special performance requirements can be summarized as follows: (1) stable hysteretic characteristics and high energy dissipation capacity; (2) high deformation capacity; (3) high low-cycle fatigue strength; (4) easy and low-cost fabrication and construction; (5) high durability; and (6) no need for replacement under continuous strong earthquakes. Jia et al [13] proposed a type of fish-bone BRB (FB-BRB), which could avoid strain concentration along the length of the core member and improve the energy dissipation capacity during a strong earthquake or subsequent repeated aftershocks. As it is essential to analyze the randomness of the response by the probability method, the seismic demand of the ductility and CPD of the BRB are concluded through the probability seismic demand analysis (PSDA) [24]. e seismic demand index of μ and CPD of the HPBRB is suggested in this paper, which could be used as a threshold value criterion for manufacturing HPBRB
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
