Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Optimal design of a novel enhanced inerter-based tuned mass damper in seismic-excited structures considering SSI effects
Araz, Onur; Shahraki, Mohammad Alibabaei
This paper proposed a novel enhanced inerter-based tuned mass damper (E-TMDI) for the control of damped single-degree-of-freedom structures due to ground acceleration. The apparatus represents an energy-dissipating passive absorber assembled from a pair of inerter elements, a pair of springs, a single mass, and a single damper. The present work directly integrates soil-structure interaction (SSI) effects within the optimization process, thereby yielding more accurate and dependable outcomes. For a clearer insight into the control mechanism of E-TMDI, the frequency-domain transfer function for responses is derived, while the influences of various model parameters on the displacement amplitude magnification factor of the superstructure both considering and neglecting SSI are examined. Four design parameters (i.e., f 1 first frequency ratio, f 2 secondary frequency ratio, ξ1 damping ratio, and κ inertance ratio of the second inerter to the first) of E-TMDI are obtained using particle swarm optimization (PSO) algorithm to minimize peak displacement amplitude of the structure. Results from the frequency domain analyses in this research indicate that the proposed E-TMDI has better efficiency and frequency band property both traditional TMD and TMDI configurations when equipped with same total mass (μ) and inertance ratio (β) in suppressing structural vibrations. Additionally, the stability of the proposed device is examined through simulations of the E-TMDI-equipped structure under a range earthquake record. The findings reveal that the E-TMDI maintains superior effectiveness even when the host structure experiences diverse earthquake events. This validation, conducted under real earthquake records, confirms the reliability of this design framework, filling a significant gap in determining the seismic control performance of E-TMDI under varying soil conditions.
- MakaleAçık Erişim2026A novel SSI-based optimization framework for non-traditional TMDI system under near- and far-fault ground motions
Araz, Onur; Forcellini, Davide
Previous studies on the optimal parameter selection of non-traditional tuned mass damper inerter (N-TMDI) system have predominantly adopted a fixed-base assumption. However, neglecting soil–structure interaction (SSI) in practical applications may lead to significant design inaccuracies and reduced control performance of the N-TMDI system. To overcome this limitation, a new design framework is proposed for the tuning of N-TMDI systems installed in primary structures subjected to ground motion by explicitly considering SSI effects. The novelty of the proposed approach consists of performing a hybrid GA-PSO optimization algorithm to study the efficiency of N-TMDI system under near- and far-field ground motions. This study investigates the influence of varying mass and inerter ratios on the system's dynamic response through frequency-domain analyses. The performance of the N-TMDI system is subsequently validated using real earthquake records, with a specific focus on the comparative effects of near-fault and far-fault ground motions under diverse soil conditions. The results demonstrate that the inerter mass ratio is the most dominant factor in enhancing seismic protection, significantly reducing structural displacement and acceleration compared to conventional TMD. Furthermore, the findings reveal that SSI and the distinct characteristics of ground motions significantly modify the system's control efficiency. This research confirms the robustness of the optimized N-TMDI design, providing a reliable and efficient strategy for seismic structural control under varied seismic scenarios.
- MakaleYalnız künye2026Energy-based wind vibration control of turbines equipped with nonlinear tuned mass damper inerter considering soil-structure interaction
Alibabaei Shahraki, Mohammad; Araz, Onur
This study evaluates the effectiveness of a Nonlinear Tuned Mass Damper Inerter (NTMDI) in mitigating wind-induced vibrations in wind turbines, with explicit consideration of soil–structure interaction (SSI). Kinetic energy is selected as the primary response metric, supported by nacelle displacement, total structural energy, soil energy absorption, acceleration reduction, and residual soil energy to provide a comprehensive assessment. A detailed numerical model is developed in OpenSees, incorporating SSI effects and subjected to turbulent wind loads generated using the Shinozuka method. NTMDI parameters are optimized using the Multi-Objective Cuckoo Search Algorithm (MOCS) to balance kinetic-energy minimization, displacement suppression, and soil-energy management. The results show that NTMDI implementation achieves approximately 45% reduction in total kinetic energy, 20% reduction in nacelle displacement, and 25% reduction in tower acceleration relative to the uncontrolled system. When SSI is considered, the NTMDI further improves performance by reducing soil energy demand by an additional 15–20%, highlighting the importance of absorber–soil coupling. Compared with traditional TMDIs, the NTMDI exhibits superior adaptability and efficiency, particularly for flexible foundations. These findings confirm NTMDIs as an effective passive control strategy for enhancing wind-turbine stability.
- MakaleYalnız künye2026Effects of earthquake frequency content and isolation thickness on seismic behavior of a structure system resting on geotechnical seismic isolation layer
Ozturk, Kasif Furkan; Cakir, Tufan; Araz, Onur
Geotechnical seismic isolation (GSI) systems aim to partially dissipate the energy before it reaches the foundation of the structure system and are therefore regarded as an important alternative to structural seismic isolation systems. In addition, the use of petroleum-derived waste materials in the GSI systems fills a significant gap in the field of waste recovery. The present study investigates the changes in the dynamic responses of a 5-story building system with and without GSI, using a set of earthquakes classified according to their frequency content. For this purpose, parametric analyses were performed using analytical methods, considering three different earthquake frequency contents and six different GSI thicknesses. Furthermore, an approach for selecting the GSI thickness was suggested. The results generally show that, for structures founded on both natural soil (NS) and GSI systems, the earthquakes with low frequency content produce responses greater than the average responses calculated for all the investigated earthquakes. Although increasing the GSI thickness has a significant effect on attenuating structural responses, increasing this thickness beyond 3 m does not lead to a relatively significant reduction in the dynamic responses of the investigated structural system. Therefore, considering the structural system, NS, rubber-soil mixtures and earthquakes examined in this study, selecting a GSI thickness in the range of 2–3 m (inclusive) may be regarded as a practical approach for mitigating the dynamic responses of the structure since further increments in thickness beyond this range provide only progressively limited improvements in structural responses. Consequently, this research may provide meaningful data for the development of vibration control strategies to improve seismic resilience of structures, and the results are expected to be useful for better understanding of the GSI applications.
- MakaleYalnız künye2026Impact of soil-structure interaction on earthquake response of high-rise steel frames equipped with TMD and FTMD optimized through cloud drift optimization
Alibabaei Shahraki, Mohammad; Araz, Onur; Ahmadi, Hossein
Vibration control of tall buildings under various seismic and foundation conditions remains a critical issue in earthquake engineering. This paper investigates the performance of Tuned Mass Damper (TMD) and Friction Tuned Mass Damper (FTMD) systems in reducing the seismic response of fixed-base and Soil-Structure Interaction (SSI) analyses of 20- and 40-storey steel moment-resisting frames. The current study uses the OpenSees software and the Cloud Drift Optimization (CDO) technique, aiming at minimizing the normalized H 2 -norm of the roof displacement. The performance of the seismic control is investigated by performing nonlinear dynamics analyses with the help of a set of 14 records, of which 7 records are far-field and the remaining ones are near-field records. Results show that both TMD and FTMD are effective in decreasing roof displacement on 20- and 40-story buildings subjected to fixed-base and SSI excitations. More precisely, results for the average reduction in roof displacement are 33.4% and 27% when FTMD is subjected to SSI loading, while those values were 10.7% and 16.5% when TMD was subjected to SSI loading in the case of 20- and 40-story buildings, respectively. Results are based on multiple variables including base shear, kinetic energy, and damping energy. The results demonstrate that the FTMD system provides superior seismic response reduction compared to the conventional TMD.
- MakaleYalnız künye2026A numerical case study on distinct inerter-based TMD configurations for SDOF structures under near-fault and far-fault ground motions
Araz, Onur; Abdo Saif, M.M.
This study presents a comprehensive optimization and performance evaluation of three distinct inerter-based tuned mass damper (TMD) configurations (C3, C4, and C6) for seismic vibration control. The optimal parameters for three different structural damping ratios (0%, 2%, and 5%) and a wide range of mass ratio (0 to 0.1) suitable for practical applications are determined in the frequency domain using the Sequential Quadratic Programming (SQP) algorithm to minimize the displacement response. To bridge the gap between complex optimization and practical engineering, novel empirical design formulas are proposed, enabling researchers to determine optimal parameters for C3, C4, and C6 configurations without requiring exhaustive computational effort. Unlike previous studies, the study presents a rigorous validation of inerter effectiveness through an extensive suite of 160 ground motions, providing a granular comparison of performance under near-fault excitations versus far-fault records. Results demonstrate that while inerter-based systems significantly outperform classical TMDs in the frequency domain, their comparative superiority in the time domain is more bound, with average response reduction improvements of approximately 5%. The inerter-based TMDs exhibit the highest efficiency in mitigating kinetic energy, followed by displacement and acceleration. Notably, the effectiveness of the control systems is found to be highly sensitive to ground motion characteristics and structural damping, where higher damping ratios consistently lead to reduced control performance. Considering the trade-off between seismic efficiency and mechanical simplicity, the C6 configuration is identified as the most viable solution for structural protection.
- MakaleYalnız künye2025Performance evaluation and optimization of nontraditional inerter-based tuned mass damper for seismic control of multi-story buildings considering SSI effects
Araz, Onur
This article presents the optimum design and performance evaluation of a control system that can be an alternative to traditional inerter-based tuned mass damper (TMDI) used in reducing vibrations in a multi-story building under earthquake effects considering soil-structure interaction (SSI). The optimum design of this system, known as NIDVA-C4 in the literature, has been carried out previously considering the randomly excited undamped main system. The key novelty of this work is to demonstrate the applicability of this system to suppress earthquake-induced vibrations in a multi-story building and to deliver more accurate and reliable results by integrating SSI effects into the optimization framework. Due to the difference in location and connection, this system is called N-TMDI in this paper. A case study from the literature featuring a ten-story building is used to implement the design process, assess performance, and conduct comparisons. The optimum parameters of the N-TMDI are obtained using the hybrid PSO-SA algorithm in the frequency domain. Validation using real earthquake records under varying soil conditions confirms the reliability of the proposed optimization framework. The coupled dynamic equations of motion for the structure - N-TMDI, accounting for SSI effects, are formulated and solved in the time domain using the Newmark-β method. An extensive parametric analysis is conducted to evaluate the effectiveness of the N-TMDI in improving the seismic response of the buildings. The results consistently demonstrate the effectiveness of the proposed protection strategy across a wide range of parametric configurations, highlighting its potential as a viable seismic mitigation strategy for a multi-story building.
- MakaleAçık Erişim2025Effect of basic parameters defining principal soil-structure interaction on seismic control of structures equipped with optimum tuned mass damper
Araz, Onur
One of the most effective systems for reducing dynamic responses of the structures subjected to earthquake excitations is tuned mass dampers (TMDs). In the traditional design theory of TMDs, the structures are assumed to be rigidly connected to the ground. Using this approach, known as the fixed foundation approach, may lead to deterioration of the performance of the TMD in cases where soil-structure interaction (SSI) is significant. Therefore, it is crucial to consider the SSI effects to obtain the optimum parameters of the TMDs. Unlike previous studies, two key parameters (i.e., structure-to-soil stiffness ratio and aspect ratio of the structure) are considered, which define the principal SSI effects on the effectiveness of TMD. For the aspect ratio of the structure, three different values (i.e., λ = 1, 2, and 4) are considered, these values correspond to the squat, ordinary, and slender structures representing traditional buildings, respectively. Four different values (i.e., a0 = 0, 0.5, 1, and 2) are also considered for the structure-soil stiffness ratio. This ratio being equal to 0 corresponds to the fixed foundation approach. This also demonstrates that the structure is constructed on hard rock. The optimum parameters of the TMD are obtained using the Jaya algorithm (JA). The proposed methodology is applied to three different buildings (i.e., 3-story, 6-story, and 12-story), and the optimum parameters of the TMD are verified using a total of 72 ground motions corresponding to NEHRP site classes C, D, and E. Numerical results show that the effectiveness of TMD is significantly affected by the basic parameters that define the principal SSI. In addition, the efficiency of the TMD is significantly related to the characteristics of the ground motions. It has been observed that TMD does not perform adequately in reducing vibrations in low-rise buildings (i.e., λ = 1) constructed on low-stiffness soils (i.e., a0 = 2).
- MakaleYalnız künye2025Influence of PGA/PGV ratio on the seismic performance of buildings with different slenderness ratios considering soil-structure interaction
Araz, Onur
In this study, the seismic performance of buildings equipped with tuned mass damper (TMD) having different slenderness ratios, subjected to ground motions with varying a wide range of PGA/PGV ratios is investigated, considering soil-structure interaction (SSI). A methodology based on hybrid Genetic Algorithm-Particle Swarm Optimization (GA-PSO) algorithm is proposed to determine the optimal parameters of TMD. For this purpose, three buildings (i.e., 3-story, 6-story, and 12-story buildings) are considered and the dynamic properties of these buildings are determined according to the provisions specified in ASCE-7. These buildings, which are frequently encountered in the traditional building stock, represent low, medium, and high-rise buildings, respectively. In the numerical analysis, three different soil types (i.e., SC, SD, and SE) and 80 ground motions are also considered. These records are divided into three different classes: high, intermediate, and low frequency content. The Newmark integration method is used to determine the dynamic responses of the structures in the time domain analysis. Numerical results show that the frequency content of ground motion and the slenderness ratio have a significant effect in reducing the peak displacement and acceleration responses of structures. The findings also demonstrate that when the PGA/PGV ratio is greater than 2, TMD shows mostly sufficient control performance for all buildings and all support conditions.
- MakaleYalnız künye2025Optimal design of inerter-assisted series tuned mass dampers for seismic vibration control of multi-story buildings
Araz, Onur
This work introduces a framework for the optimal design of inerter-assisted series tuned mass dampers (STMDI) placed at the top story of a multi-story building under ground motion and performs comparative research to assess its effectiveness against conventional TMDI. The identical inertance ratio and total mass ratio are taken into consideration for the optimization of both control systems. In the frequency-domain analysis, the five design variables of the STMDI are optimized based on the minimization of the peak amplitude of the displacement transfer function at the top story of the building using the genetic algorithm (GA). The optimized variables are damping ratios (ξ1and ξ2), tuning frequency ratios (f1and f2), and mass ratio of the first to second TMD mass (µh). The proposed control system is applied to a 4-story, an 8-story, and a 16-story case-studies, and the optimal parameters are verified using eighty-five historical benchmark earthquakes in time domain analysis. These records are divided into three different groups according to their frequency content, i.e. PGA/PGV ratio: high, intermediate, and low. The results demonstrate that the STMDI performs better than the TMDI at the same mass and inertance ratio, especially at excitation frequencies close to resonance. The most important advantage of STMDI compared to TMDI is that it provides this performance in a wider frequency range and in an almost similar way. Finally, the seismic performances of STMDI and TMDI are compared considering ground motions with different frequency content.
- MakaleYalnız künye2025Assessment of Seismic Responses of Square-Hollow-Section Joints in a Lattice Girder with Soil-Structure Interaction
Ozturk, Kasif Furkan; Ozyurt, Emre; Araz, Onur; Cakir, Tufan
The fixed base approach is widely used to obtain the seismic behaviour of Square Hollow Section (SHS) joints in a lattice girder. However, in some cases where soil-structure interaction (SSI) can be relatively significant, this approach may result in incorrect acquisition of the natural periods and dynamic responses of the lattice girders using welded tubular joints. This situation may negatively affect the safety of the structure by causing an underestimation of the dynamic loads acting on the structure. Therefore, this study evaluates the seismic behaviour of SHS joints in a typical lattice girder exposed to different ground motions considering SSI. A nonlinear finite element analysis software, Abaqus, performs the dynamic analyses considering six earthquake excitations with three different frequency contents (a ratio of peak ground acceleration (PGA) to peak ground velocity (PGV)) and four different soil types. After verifying the numerical model, it is determined that 3D solid elements should be used to capture the actual seismic behaviour of the tubular joints in a steel truss frame with or without SSI. A comprehensive parametric study is then carried out to evaluate the peak displacement and stress values on the SHS joints with and without SSI under different ground motions with different PGA/PGV ratios. The findings show that the stresses are concentrated around the column and bottom chord connection region. Besides, the SSI mechanism significantly affects the peak stress and displacement values of the SHS joints, especially in soft soil types. Furthermore, it is observed that the PGA/PGV ratio significantly changes the seismic responses of the steel truss frame.
- MakaleYalnız künye2025Effect of frequency content of ground motion on seismic response of buildings with variable aspect ratio including soil-structure interaction
Kaya, Dilek; Cakir, Tufan; Ozturk, Kasif Furkan; Araz, Onur
Soil-structure interaction (SSI) may lead to reduction, amplification or negligible change in structural responses depending on the relationship between the nature of excitations and subsoil conditions. Since neglecting SSI effects may cause uncertainties in seismic design, it is crucial to consider them during the design process. Another important factor affecting the dynamic behavior of structures interacting with the ground is the dynamic properties of the structures. To consider this effect, three buildings with 4, 8, and 12 stories designed in accordance with the Turkish Building Earthquake Code (TBEC-2018) are analyzed. The aspect ratios of these structures are 2, 4, and 6, corresponding to squat, ordinary, and slender structures, respectively. The primary objective of this study is to simulate the combined effects of these key parameters on the dynamic response of reinforced concrete structures. In the time history analyses, six ground motions classified by three different frequency contents are considered. 3D finite element models of SSI systems are established using ANSYS software. The usability of the numerical models is demonstrated for both SSI and fixed-base cases through three different analytical approaches. The displacement, acceleration, and stress responses are examined through time history analyses. The results indicate that the SSI is not negligible and neglecting the SSI is an oversimplification that does not lead to always-conservative predictions. Moreover, both the frequency content of the excitation and the structural aspect ratio are found to be decisive parameters in seismic response.
- MakaleAçık Erişim2024Effect of PGV/PGA ratio on seismic-induced vibrations of structures equipped with parallel tuned mass dampers considering SSI
Araz, Onur
Tuned mass damper is one of the effective methods used to reduce dynamic loads in structures under the influence of environmental loads such as earthquakes, wind, and traffic loads. In the current TMD design, the fixed base approach is mostly considered when determining the dynamic properties of the structure. However, in cases where the structure-soil interaction (SSI) is important, the frequency values of the structure are significantly different from those obtained for the fixed foundation approach. This situation negatively affects the performance of TMD operating in a narrow frequency range. Therefore, using a control system consisting of multiple TMDs connected in parallel (MTMD) instead of a single TMD may be a promising solution for the control of structural vibrations. In this study, a parameter design and efficiency assessment of MTMD for reducing the seismic responses of the structure considering SSI is studied. The particle swarm optimization (PSO) algorithm is adopted to obtain the optimum parameters (i.e., damping ratio, frequency ratio, and frequency bandwidth) of the MTMD. The effects of different support conditions, number of TMD units, and peak ground velocity (PGV) / peak ground acceleration (PGA) ratio on the performance of MTMD are also evaluated comprehensively. The dynamic responses of the structure are obtained under 42 near -fault ground motions from the time history analysis. The results reveal that ground motions with low PGV/PGA ratio can significantly increase the responses of the structure for both with and without SSI cases. Moreover, it has been observed that optimized TMDs placed parallel to the top floor of the structure are effective in reducing the seismic responses of a ten-story building considering SSI.
- MakaleAçık Erişim2024Performance of differently arranged double-tuned mass dampers for structural seismic response control including soil-structure interaction
Araz, Onur; Elias, Said
Reducing vibrations occurring in structures under environmental loads makes a significant contribution to the development of structural safety. Tuned mass dampers (TMD) are one of the systems commonly used to control structural vibrations. Since TMD is adjusted according to the dominant frequency of the structure, factors that may cause changes in the frequency of the structure can significantly reduce the effectiveness of TMD. One of the main factors that can cause changes in the frequency values of the structure is the interaction between the structure and the soil. To overcome this situation, it is recommended to apply control systems consisting of multiple TMDs (MTMD) to the main structure instead of a single TMD. MTMD systems are arranged in two different types, serial and parallel. In this paper, a methodology that considers the structure-soil interaction (SSI) is presented for the optimum design of control systems with different configurations placed on a main structure under the influence of ground motion. To research the SSI effects, the TMDs-structure coupled system is supported by rocking and swaying springs and the corresponding dashpots, and then the equations of motions of the structural system are derived. In the optimization process based on particle swarm optimization in the frequency domain, different soil types, configuration types, and mass ratios are considered. The efficiency of optimum TMDs arranged in series and parallel is also evaluated using near and far fault ground motions in the time domain. Numerical results show that if structures are constructed on soils with low shear wave velocities, ignoring SSI can significantly change the design parameters and effectiveness of the control system.
- MakaleYalnız künye2023Seismic-induced vibration control of a multi-story building with double tuned mass dampers considering soil-structure interaction
Araz, Onur; Elias, Said; Kablan, Feyza
This paper presents a methodology for the optimization of double tuned mass dampers (TMDs) positioned on the top floor of a multi-story building subjected to ground motions considering soil-structure interaction (SSI). In the optimization process, it is considered that double TMDs are connected both in series and in parallel. STMD and PTMD are used to denote the series TMDs and parallel TMDs, respectively. The equations of motion for an n-story shear building controlled by STMD and PTMD are derived by considering the SSI effect and the optimum parameters of both devices are obtained by minimizing the amplitude of the displacement transfer function for the top floor of the building in the frequency domain analysis. The effectiveness of the PTMD and STMD designed using the Jaya algorithm (JA) is verified by numerical examples of a ten-story shear building under twelve earthquake records with different frequency content and the comparison with the traditional TMD is also performed. In order to investigate the effect of earthquake frequency content on the control performance of the TMDs, earthquakes considered are divided into three different groups as low, intermediate, and high-frequency contents. In addition, the influence of the soil stiffness on the optimum parameters and effectiveness of the PTMD and STMD is discussed. Numerical results show that the optimally designed PTMD and STMD effectively suppressed the maximum floor displacements and accelerations of the building. It is also shown that SSI effects can be ignored when the building is built on stiff soil. In addition, it is concluded that the SSI and earthquake frequency content have a significant effect on the control performance of TMDs and the seismic response of the building.
- MakaleYalnız künye2023Effect of foundation embedment ratio in suppressing seismic-induced vibrations using optimum tuned mass damper
Araz, Onur; Cakir, Tufan; Ozturk, Kasif Furkan; Kaya, Dilek
Tuned mass damper (TMD), which is used in structures to mitigate the dynamic responses caused by environmental loads, is tuned according to the dominant frequency of the structures. The dominant frequency of structure built on soil with low stiffness is significantly affected by the soil-structure interaction (SSI). In previous studies, only the surface foundation case is considered to investigate the design parameters of TMD considering SSI effects and the embedment depth of the foundation is neglected in these studies. Thus, this paper investigates the optimization of TMD for mitigation of responses of a high-rise building considering various depths of embedment and soil properties. The optimum parameters of TMD are investigated using five different optimization algorithms (i.e., simulated annealing, sequential quadratic programming, genetic algorithm, pattern search, and particle swarm optimization). The objective function minimizes the peak acceleration amplitude at the top of the structure. The effectiveness of optimum TMD is verified to use 20 near-fault pulse-like ground motions. The comparisons show that the embedment ratio of the foundation and the soil properties significantly affect the optimization of TMD.
- MakaleYalnız künye2023Influences of Wall Configurations on Earthquake Behavior of Cantilever Retaining Walls Considering Soil-Structure Interaction Effects
Ozturk, Kasif Furkan; Cakir, Tufan; Araz, Onur
Cantilever walls are frequently and necessarily built not only in earthquake prone regions but also on different foundation subsoils with various physical and mechanical characteristics. The response of these structures is a complicated soil-structure interaction (SSI) problem, in which the relative stiffness between the soil and structure is of critical importance. In addition to different soil conditions and earthquake motions, the wall configurations have an important role in the cantilever retaining wall design. Thus, the major objective of this work is to investigate the effects of various configurations on seismic response of the cantilever retaining walls considering SSI. Accordingly, the seismic response of the interaction systems is revealed using the 3D finite element models (FEM) in time domain, assuming linearly elastic behavior for the wall, and elastoplastic behavior for backfill and foundation soil. Viscous absorbent boundaries are employed to both simulate radiation scenario and avoid undesirable wave reflections generated by soil lateral boundaries. Backfill-wall interfaces are modeled using the unidirectional interface elements with nonlinear force-deflection abilities. The interaction systems are analyzed considering three different cantilever wall configurations (inverted T-type, L-type, and the wall with a base key), four different ground motion records, and four different subsoil systems. Nonlinear seismic analyses are carried out to visit how considering the variation of these parameters influences the wall behavior. The results from parametric studies show that the wall configuration, SSI effects and ground motions are remarkably influential on seismic responses of the cantilever walls such as the stresses and horizontal displacements.
- MakaleYalnız künye2023Optimum tuned tandem mass dampers for suppressing seismic-induced vibrations considering soil-structure interaction
Araz, Onur; Noroozinejad Farsangi, Ehsan
In recent studies, it has been stated that tuned tandem mass dampers (TTMD) will be a practical mechanical solution to reduce the dynamic responses of structures under seismic excitations. However, since TTMD is tuned based on the dominant frequency of the superstructure, ignoring the soil-structure interaction (SSI), it may cause a notable deterioration in the control performance of the control devices. Thus, a methodology for the optimum design of TTMD positioned on the top story of a high-rise building due to near-fault pulse-like ground motions considering potential SSI effects has been investigated in this paper. Firstly, the TTMD is located on the top story of a well-known 40-story shear building, and the equations of motion for soil-structure-TTMD interaction are derived. Based on the sequential quadratic programming (SQP), the tuning parameters of TTMD are then found for different support conditions in the frequency domain. The efficiency of SQP is also compared with two meta-heuristic algorithms (i.e., simulated annealing and pattern search algorithms). The effectiveness of optimum TTMD is tested using 30 near-fault pulse-like ground motions using time-domain analyses. Numerical results showed that the optimum TTMD is more effective in suppressing the maximum displacement and inter-story drift of the building, considering SSI. It is also found that the frequency content of the earthquake, as well as the pulse period of the earthquake and soil type, has a significant effect on the control performance of the TTMD.
- MakaleAçık Erişim2022Optimization of tuned mass damper inerter for a high-rise building considering soil-structure interaction
Araz, Onur
The dynamic responses of the buildings and the optimum parameters of tuned mass damper inerter (TMDI) may change significantly when soil-structure interaction (SSI) is considered. Thus, it is necessary to consider the effect of the SSI in the optimization of TMDI. The study aims at proposing a methodology for optimization of TMDI parameters in reducing maximum structural responses of a high-rise building under earthquake considering the SSI effects. The equations of motion for time-domain analysis are derived for obtaining seismic-induced vibrations of a multi-story shear building with TMDI when the SSI is considered. An improved particle swarm optimization (IPSO) is used to obtain the optimum parameters. The aim of the optimization is to reduce the amplitude of the acceleration transfer function (ATF). The effectiveness of the optimally designed TMDI is assessed for twelve earthquake records with different frequency contents. The effect of the different mass ratios (µ), inertance ratios (β) and support conditions on control performance of the TMDI are investigated in detail. Numerical results proved that the SSI effect and the inertance ratio have a significant impact on the optimal design and effectiveness of the TMDI. From the seismic analysis results, it is seen that the controlled displacement response usually increases with the increase in the inertia ratio for both the fixed and flexible foundation, and a lower seismic response is obtained in the building controlled by TMD compared with the TMDI with different inertance ratios.
- MakaleYalnız künye2022Effect of earthquake frequency content on seismic-induced vibration control of structures equipped with tuned mass damper
Araz, Onur; Cakir, Tufan; Ozturk, Kasif Furkan
The main goal of this paper is to investigate the influence of the earthquake frequency content on the optimization of tuned mass damper (TMD) for multi-story buildings. Earthquake frequency content is divided into three groups (i.e., low, intermediate and high frequency content) according to the ratio of peak ground acceleration to the peak ground velocities. Time-domain analyses are performed to obtain the dynamic responses of 10-story and 40-story shear buildings equipped with a TMD under twelve different earthquake records. Advanced firefly algorithm is used to obtain the optimum parameters of the TMD such as the frequency ratio and the damping ratio. The optimization criterion is selected as the minimization of the maximum top story displacement of the building with TMD. The optimum parameters of TMD designed by this paper and its control performance are compared with those of other previous works available in the literature. Compared to the other methods, the optimum TMD designed by this study especially performs better in reducing the maximum top story displacements. Furthermore, it is discussed why TMD is ineffective in reducing the maximum floor accelerations of 40-story building, and then the effect of different mass ratios and objective functions in reducing the maximum responses of both buildings under critical earthquake excitation is investigated in detail. The results also show that the frequency content of earthquake ground motions has a significant effect on the optimum parameters of TMD and its control performance.