# Development of a New Rubber Buckling-Restrained Brace System for Structures
## 1 Introduction
The models displayed that the maximum displacements of the structure were within the target displacements, and BRBs dissipated energy inelastically while the rest of the structural members remained elastic [46]. An alternate application of BRBs was approached by [PERSON], [PERSON], and [PERSON] (2006). They report on the seismic performance of single-angle X braces [47]. The study comprised the cyclic testing of single-angle braces, experimental static loading, and shake tables on a large scale. The results indicated that the single angle with sufficient connection details performed well, with cyclic deformations of more than 6% axial strain before failure. The experimental testing was subjected to the scaled-up 1940 El Centro earthquake. The experimental results in brace axial strains indicated 1.6% less than the calculated displacement capacity of the X-breaced cross frames (which is 6%), the system also displayed no strength degradation and had a comparatively low post-yield stiffness, effectively behaving as a structural fuse. Ultimately, the X brace system reduced the elastic base shear seen up to 50%. Based on FEMA, the performance-based method (PBD) is a technical concept. It is made up of a series of exercises employed in order to construct a system with a given probability of not accomplishing such damage levels, considering a possible spectrum of theoretical earthquakes that might impact it (FEMA-P58, 2012). Under PBD, developers are able to recognize a risk standard for any of the multiple types of earthquake hazards listed. As seismic risk is a probabilistic theory, it must be measured by quantifiable values to be understandable. Due to the superb hysteretic behavior of BRBs, they have become more accepted than ever to be implemented as an earthquake-resistant system in structures [48]. They have been verified to be a functional technique to employ BRBs in structures for seismic retrofitting. For steel structures with BRBFs, the seismic demand can be considerably decreased by mitigating any damage to BRBs [49]. In order to decrease the damage to structures during earthquake events, a suitable structural design method is required to be adapted to use BRB energy dissipation capacity. The conventional strength-based seismic design (SBSD) method is unable to estimate BRBFs' inelastic behavior. For this purpose, performance-based seismic design (PBSD) methods have been widely applied. Also, the direct displacement-based seismic design (DBSD) method is becoming accepted in the engineering community as an efficient method to design BRBFs [45,50]. However, earthquake damage is closely related to the hysteretic energy of the structural cumulative, which is not measured in the DBSD method [51]. Recently, some researchers also utilized energy methods to anticipate the damage state of structures [52, 53, 54]. Accordingly, as a substitute, these types of design methods such as SBSD, DBSD, and energy-based seismic design (EBSD) have increasingly been used in BRBF design procedures [55, 56, 57, 58, 59]. [PERSON] et al. (2020) analyzed the seismic performance of dual systems combining Buckling-Restrained Braced Frames (BRBFs) with moment-resisting frames (MRFs). These systems enhance energy dissipation, stiffness, and reparability. The results showed that high base shear ratios (\(\alpha>3\)) reduce cumulative ductility demands but increase residual displacements, potentially exceeding reparability limits. Residual displacement variability was significant, emphasizing its importance in post-earthquake assessments. While higher \(\alpha\) values control accelerations and ductility demands, they also amplify residual drifts [60]. The study validated the SEI/ASCE 7-10 limit of \(\alpha=3\) and provided practical recommendations for balancing acceleration control and residual capacity in system design [61]. [PERSON] and [PERSON] (2024) analyzed a two-span bridge with a post-tensioned concrete pier and a Buckling-Restrained Brace (BRB) using a validated 3D nonlinear numerical model.