Torsional control of plan-asymmetric structures using the torsional balance concept and optimized viscous dampers: A fragility-based assessment
Document Type
Journal Article
Publication Title
Iranian Journal of Science and Technology - Transactions of Civil Engineering
Publisher
Springer
School
School of Engineering
Abstract
Despite advancements in seismic regulations for asymmetric structures, past earthquakes have revealed their significant vulnerability, resulting in substantial damage and even collapse. The torsional-lateral coupling in such structures increases lateral displacements at the endpoints of the structural plan, leading to irregular deformation demands in seismic-resistant frames. To address these challenges, previous studies have recommended the use of energy dissipation devices, such as viscous dampers, to mitigate the torsional response of asymmetric structures. This research aims to determine the optimal distributions of viscous dampers to reduce the torsional-lateral correlation in these structures, employing the concept of torsional balance. A five-story steel structure with varying mass eccentricities is modeled in the OpenSees software. The optimal distribution of viscous dampers, both in the plan and along the height of the structure, is determined using the torsional balance concept and the particle swarm optimization (PSO) algorithm. Subsequently, incremental dynamic analysis (IDA) and fragility curve generation are conducted to evaluate the seismic damage and the probability of failure in asymmetric structures equipped with viscous dampers. The results indicate that the optimal distribution of viscous dampers significantly improves the torsional response of such structures and reduces seismic damage, as well as the likelihood of exceeding the performance level of structure. Furthermore, the study highlights that controlling the torsional response of asymmetric structures depends on multiple factors, including mass eccentricity, supplemental damping ratio, and damping eccentricity.
DOI
10.1007/s40996-025-01863-w
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Comments
Shahmohammadian, A., Mansoori, M. R., Mahmoudi, N., & Anahid, H. (2025). Torsional control of plan-asymmetric structures using the torsional balance concept and optimized viscous dampers: A fragility-based assessment. Iranian Journal of Science and Technology, Transactions of Civil Engineering. Advance online publication. https://doi.org/10.1007/s40996-025-01863-w