Jul 2026· The eurasia proceedings of science, technology, engineering & mathematics· Vol 40, pp. 296-303· 0 citations· 17 references
Abstract
Tuned Mass Dampers (TMDs) are widely adopted passive vibration control devices used to mitigate structural oscillations induced by wind and seismic actions. Conventional TMD systems typically involve relatively small auxiliary masses installed near the top of tall buildings. This paper investigates an alternative strategy for seismic retrofitting of existing structures based on large mass ratio TMDs obtained through building superelevations. In this approach, one or more additional storeys supported by seismic isolation devices behave as large tuned masses capable of reducing structural response during earthquake excitation. A comprehensive parametric numerical investigation is carried out in order to evaluate the influence of the mass ratio, structural period and damping characteristics on the effectiveness of the system. The results are summarized in a set of design charts that allow engineers to determine optimal tuning parameters. In particular, by using the obtained design abaci they can find a solution which minimizes both displacement and acceleration.
Control systems such as base isolators and dampers are widely used to reduce the seismic energy input to structures. Among passive control devices, Tuned Liquid Dampers (TLDs) mitigate structural vibrations through sloshing of the contained liquid, which generates counteracting inertial forces without requiring external power. The effectiveness of TLD systems strongly depends on the selected mass ratio. This study evaluates the influence of TLD mass ratio on the seismic performance of a 10-story reinforced concrete frame building, with particular emphasis on plastic deformation demands and seismic-induced residual displacements. TLDs with different mass ratios are considered to assess their impact on interstory drift, column plastic rotations, and post-earthquake residual response. The results indicate that while increasing the mass ratio may lead to higher plastic deformation demands in certain cases, it consistently reduces residual displacements. Among the investigated configurations, a 5% mass ratio provides the most balanced performance, achieving significant reductions in residual displacement without substantial amplification of deformation demands. These findings highlight the importance of carefully tuning TLD mass ratio to achieve improved post-earthquake functionality while avoiding adverse increases in structural demand.
Birkan Dağ, Muzaffer Börekçi, M. Gençoğlu· Dicle Üniversitesi Mühendisl...· 0 citations
Efficient and practical seismic control of structures-particularly through isolation systems-remains a significant challenge due to high implementation costs and construction complexity. Moreover, their application in retrofitting existing structures often requires extensive modifications.To address these challenges, this study proposes a novel and cost-effective seismic control system, termed the Ridge-Isolated Tuned Mass Damper (RITMD), which integrates the advantages of tuned mass damping and seismic isolation. A reduced-order two-degree-of-freedom (2DOF) model is developed to capture the coupled dynamic behavior of the primary structure and the RITMD system. An optimization framework based on the Particle Swarm Optimization (PSO) algorithm is employed to determine the optimal tuning parameters. Subsequently, closed-form design expressions are obtained using nonlinear regression analysis to facilitate practical engineering applications .The proposed approach is further extended to three-dimensional structural systems, and its performance is evaluated through nonlinear time-history analyses under bidirectional earthquake excitations. The results demonstrate that the RITMD system significantly reduces structural responses, including displacements, accelerations, inter-story drifts, torsional demands, and their corresponding root-mean-square (RMS) values.Overall, the proposed system provides an efficient, practical, and versatile solution for enhancing the seismic performance of both new and existing structures.
Wind turbines in seismically active regions are increasingly vulnerable to earthquake-induced vibrations due to their growing height and flexibility. Effective vibration control is therefore essential to ensure structural safety and operational reliability. This study examines the performance of a novel compact nonlinear magnetic damper with non-contact restoring and damping force generation in mitigating the seismic response of wind turbine towers. The tower is modeled through a three-degree-of-freedom modal representation, corresponding to the first three fore–aft mode shapes obtained from a finite element–based modal analysis. A synthetic acceleration record was then developed by averaging the frequency content of five well-known earthquakes to represent their dynamic characteristics, providing a comprehensive excitation spectrum for evaluation. The damper parameters were optimized using a Bayesian optimization framework, with the root-mean-square of tower-top displacement adopted as the objective function. The optimized configuration was subsequently assessed under each individual earthquake record to evaluate its robustness. Results show that the proposed damper, together with the optimization scheme, achieves 36–65% reductions in RMS tower-top displacement and maintains consistent performance across different ground motions. The findings demonstrate the effectiveness and adaptability of the magnetic damper in enhancing the seismic resilience of wind turbine structures and provide a promising direction for integrating smart damping technologies into renewable energy systems.
Nonlinear velocity dampers (NVDs) embedded in coupling beams may enhance the seismic performance of frame–core tube structures by dissipating energy and limiting structural damage. This study evaluates the seismic performance of a 20-story reinforced concrete (RC) frame–core tube building incorporating NVD-equipped coupling beams. Parametric studies are conducted at the frequent earthquake (FE) level, and nonlinear time-history analyses are performed at the design-basis earthquake (DBE) and rare earthquake (RE) levels. The results show that wall-pier flexure is the primary contributor to damper deformation, and mid-span placement is found to be relatively favorable. The optimal damping coefficient varies with the engineering demand parameters, whether base shear, drift, or additional damping, indicating that damping coefficient should be chosen based on a balanced consideration. For the N. Palm Springs ground-motion record considered in the damage assessment, the NVD-equipped models exhibit less flexural damage than the reference model for varying damping coefficients at both DBE and RE levels. These findings provide case-specific design guidance for applying NVD-equipped coupling beams in comparable RC frame–core tube buildings.
Shen Liu, Bo Li, Hui Wang et al.· Buildings· 0 citations
Earthquakes produce significant lateral forces on structures, which may lead to excessive displacement, structural
instability, and collapse if proper seismic resistant measures are not adopted. The present study focuses on the comparative
seismic performance evaluation of a G+11 reinforced cement concrete (RCC) building incorporated with different vibration
control system using ETABS 20. The building was analyzed for Seismic Zone V using the Response Spectrum Analysis (RSA)
method in accordance with the provisions of IS 1893 (Part 1): 2016. Six structural models were considered in the study, namely
bare frame structure, fluid viscous damper model, friction damper model, X-bracing model, shear wall model, and lead rubber
bearing (LRB) base isolated model. The seismic performance of each model was evaluated based on parameters such as
maximum storey displacement, storey drift and storey shear. The results obtained from the analysis indicate that the Shear Wall
model provides the most effective reduction in displacement and drift due to its Enhanced stiffness, although the shear wall and
bracing systems significantly improve structural stiffness but attract higher seismic forces hence greater base shear than bare
frame model. The fluid viscous damper and friction damper showed overall good seismic performance by reducing the overall
displacement, drift and storey shear without attracting higher seismic forces. The base isolated model increases the displacement
due to increased flexibility in the structure but reduces drift and force transmission into the structure. The study concludes that
vibration control systems considerably enhance the seismic performance of RCC structures and assist in improving structural
safety in earthquake-prone regions.
Utkarsh Mishra, Rakesh Grover· International Journal for Re...· 0 citations
This study investigates the performance of a tuned mass damper inerter (TMDI) in enhancing the seismic performance of structures by focusing on the concept of effective damping ratio (EDR) and its enhancement through the effective damping ratio enhancement (EDRE) approach. An analytical model is developed for a single‐degree‐of‐freedom system subjected to stochastic excitation, from which closed‐form expressions are derived to identify optimal design parameters, including frequency ratio, damping ratio, and mitigation ratio. The proposed formulation provides a direct way to quantify how the TMDI contributes to the overall damping of the system and how this contribution can be maximized for improved response control. The analytical results are validated against numerical optimization, showing close agreement and, in many cases, improved accuracy of the closed‐form solutions. A detailed parametric investigation is carried out to understand the influence of key parameters such as inertance‐to‐mass ratio, structural damping, and detuning on system behavior. The approach is then extended to multi‐degree‐of‐freedom base‐isolated structures and evaluated under both stochastic excitations, modeled using the Kanai–Tajimi spectrum, and recorded near‐fault and far‐field ground motions. The results demonstrate that TMDI systems can significantly reduce structural responses, with the EDR and EDRE playing a central role in governing performance. The effectiveness of the EDRE mechanism is found to depend on the level of inherent structural damping, becoming more pronounced within specific damping ranges. Overall, the study presents a physically transparent and computationally efficient framework for designing TMDI systems to enhance seismic resilience in both conventional and base‐isolated structures.
K. K. Kiran, Mir Basar Suhaib, Z. R. Wani et al.· Earthquake spectra· 0 citations
