Original Article Journal of Intelligent Material Systems and Structures 1–15 Ó The Author(s) 2019 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1045389X19828502 journals.sagepub.com/home/jim Development and design of a new self- centering energy-dissipative brace for steel structures Amir Kari 1 , Mehdi Ghassemieh 2 and Baitollah Badarloo 1 Abstract Buckling-restrained braces are able to provide significant energy dissipation along with large ductile capacity through their excellent hysteretic behavior. However, due to their lack of recentering capability, buckling-restrained braced frames experience large residual drifts following a strong earthquake, leading to enormous repair costs. To overcome this shortcoming, super-elastic shape memory alloy braces with excellent recentering capacity have been introduced as a viable alternative to steel braces. Nevertheless, their energy dissipation capacity is usually low for seismic applications. This article proposes a robust self-centering energy-dissipative brace to be used in structural frames. The brace is capa- ble of providing adequate energy dissipation capacity in the structure while simultaneously bringing the structure to its original configuration after the earthquake. Keywords Shape memory alloy, buckling-restrained brace, energy dissipation, recentering, super-elastic 1. Introduction The design of structures to remain elastic against seis- mic loads secures them against damage. However, for reasons of economy and architecture, it is not accepta- ble to design and build conventional structures to respond elastically to severe earthquakes. As a conse- quence, the design codes allow engineers to design structures for lower forces than those that would be required if the structure were to remain elastic, pro- vided that the capability of the displacement-based components to dissipate adequate amount of energy through undergoing large inelastic deformations is ensured. This is primarily attributed to the principle of the conservation of energy as stating that the external energy (in this situation: the energy of the earthquake applied to the structure) must be equal to the internal energy (in this situation: the amount of energy dissi- pated by structural members). 1.1. Buckling-restrained braces Buckling-restrained braces (BRBs) consist of two main components: a steel core that carries the axial force and a sleeve that is filled with cement grout or any other inert filler in order to prevent the steel core from buck- ling in compression while allowing it to yield in com- pression and tension. Unlike traditional braces, considerable amount of energy can be dissipated through the stable and predictable hysteretic behavior of BRBs, as seen in Figure 1, while providing large duc- tility for the structure. Due to their robust perfor- mance, extensive research has been carried out on the seismic behavior of buckling-restrained braced frames (BRBFs) (Kim and Choi, 2004; Kim and Seo, 2004; Sabelli et al., 2003; Tremblay et al., 2006; Wigle and Fahnestock, 2010). In addition, their application in seismic retrofit of existing structures has been investi- gated (El-Bahey and Bruneau, 2011; Teran-Gilmore and Ruiz-Garcia, 2011). Although BRBs offer very positive energy dissipation capacity, their large residual deformation after unloading results in clear permanent lateral displacement of the structure. This phenomenon is a significant shortcoming of steel, regardless of being buckling-restrained or buckling-allowed, which could make the structure challenging, and sometimes eco- nomically unreasonable to be repaired after a severe 1 Department of Civil Engineering, Qom University of Technology (QUT), Qom, Iran 2 School of Civil Engineering, University of Tehran, Tehran, Iran Corresponding author: Amir Kari, Department of Civil Engineering, Qom University of Technology (QUT), Qom 3718146645, Iran. Email: kari@qut.ac.ir