## 7 Conclusions  
The current research investigated the fatigue life of BRBs elements and their effect on the overall performance of high-rise steel buildings by predicting the sequence of multi-hazard scenarios in the building lifetime. Toward this objective, first, a 20-story moment resisting frame is designed to resist the gravitational loads; then, the simplified method presented in the JSSI manual is applied to design the required BRB elements to satisfy the 1% story drift ratio (design target) imposed by the lateral excitation. In the next step, the Poisson process-based procedure is used to randomly approximate the probable multi-hazard scenarios during the project's lifetime. The proposed concept is applied to generate five random scenarios, and the target building performance under multi-hazard scenarios is assessed. The main conclusions of the study are drawn as follows.  
* Although for the design earthquake and wind loads, as recommend by AIJ (2019), the target building satisfies the 1% story drift ratio, but the building performance under multi-hazard scenarios is about 2.0-5.0 times larger. It is because, first, the estimated intensities of multi-hazard events from the proposed procedure are slightly larger in comparison to the design earthquake; second, the contribution of multi-hazard scenarios to the progressive damage of BRBs amplifies the overall building's performance.  
Figure 20: Maximum ductility demand of selected BRBs under multi-hazard scenarios.  
Under the multi-hazard scenarios, the progressive damage of BRBs that are in upper stories is considerably smaller than that of the BRBs located in lower stories. This is indicating that the BRBs in lower stories are severely prone to low-cycle fatigue damage in the building service period.
* The progressive damage of BRBs under multi-hazard scenarios, which is studied in terms of cumulative damage index (CDI), cumulative ductility factor (CDF), plastic strain energy (PSE), and maximum ductility, reveal that the fatigue life of a BRB is a multi-criteria issue. It is found that although the BRBs can satisfy one or two of the thresholds, under the successive application of wind and earthquake excitation, the devices fail to endure all the aforementioned criteria. Corresponding to the designated criteria, the fatigue life is variable as well. Therefore, the current study recommends the multi-criteria be incorporated in the design phase of the high-rise building with BRBs.
* Considering the multi-criteria investigated in this study, this study observed that the effective service life of BRBs is much smaller than the design service life.
* Under the successive analysis of multi-hazard scenarios, the ductility demand of BRBs is three times larger than that during Level-2 earthquakes.  
Conceptualization, T.S. and A.N.; methodology, A.N. and T.R.; software, T.S.; writing--original draft preparation, A.N.; writing--review and editing, T.S.; supervision, T.S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest.