Seismic Protection of Multi-Story Structures With Novel Vibration Absorption Devices Combining Negative Stiffness and Inerter

Kapasakalis, Konstantinos A.; Florakis, Georgios; Antoniadis, Ioannis; Sapountzakis, E. J.

doi:10.7712/120121.8765.19225

Cited by 6 publications

(6 citation statements)

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“…As mentioned in section 3, the design values of the EKD-R system are derived from the optimization procedure. More specifically, based on previous work [15,20], realistic values for the generated NS and the viscous dampers implemented are -130 kN/m and 20 kNs/m per tn of total superstructure mass, respectively. The total mass of the benchmark building is 130 tn, and the values of the EKD-R components (for each installed device), obtained from the optimization process, are presented in Table 1.…”

Section: Benchmark Building Geometry and Characteristicsmentioning

confidence: 99%

3d Numerical Investigation of an Extended Kdamper Absorber for Seismic Retrofitting of Low-Rise Buildings

Mantakas,

Kapasakalis,

Kalderon

et al. 2023

Proceedings of the 8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

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Research in the field of seismic protection has progressed significantly, starting from the use of simple elastomeric bearings that require a reduction of the system's fundamental frequency to control the dynamic response of the superstructure, to more advanced vibration control devices that incorporate the use of additional oscillating masses and negative stiffness elements. Examples of these devices are the Tuned Mass Damper (TMD), the Quasi-Zero oscillators (QZSs) as well as the KDamper concept that is based essentially on a combination of appropriate stiffness, damping and mass elements, including a negative stiffness element. In this study, a passive KDamper-based vibration absorber is implemented at the base level of a typical existing building, between the foundation and the superstructure, as a means of seismic retrofitting. A mathematical model is formulated, and an optimization procedure is undertaken using both EC8 compatible artificial accelerograms as well as real earthquake records. Geometrical and manufacturing limitations are accounted for, regarding the realization of the negative stiffness mechanics and the rest vibration control components. A sophisticated 3D finite element model is subsequently generated aiming to take into account soilstructure interaction, material non-linearities and effect of geometry and location of the device in a realistic manner. Results indicate the beneficial effect of the system in the dynamic behavior of the structure and highlight the applicability of the system as well as limitations that should be considered in future research.

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Section: Benchmark Building Geometry and Characteristicsmentioning

confidence: 99%

3d Numerical Investigation of an Extended Kdamper Absorber for Seismic Retrofitting of Low-Rise Buildings

Mantakas,

Kapasakalis,

Kalderon

et al. 2023

Proceedings of the 8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

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“…The negative stiffness element kN, in the proposed configuration of EKD, is realized with pre-compressed springs. Based on previous indicative designs of KDamper with pre-compressed springs by Antoniadis et al [12] and Kapasakalis et al [27], for a total superstructure mass of 300 tn, a realistic value of kN is -34171 kN/m. In this work, the negative stiffness element absolute upper value is |30000| kN/m.…”

Section: Evaluation Of Optimization Constraints and Limitationsmentioning

confidence: 99%

“…This vibration control system has been examined for the protection of bridges [13][14][15][16][17] wind turbines [18,19] and structural systems [20,21]. In addition, the KDamper is implemented as an Absorption Base (KDAB) in the bases of structures [22][23][24][25][26][27][28]. In the recent work of Kapasakalis et al [28], the KDAB is proven to be a possible supplement to BI, or can be alternatively implemented as a "stiff absorption base".…”

Section: Introductionmentioning

confidence: 99%

Advanced Negative Stiffness Vibration Absorbers Coupled With Soil-Structure Interaction for Seismic Protection of Buildings

Kapasakalis¹,

Alvertos²,

Mantakas³

et al. 2020

XI International Conference on Structural Dynamics

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Throughout the past decades, seismic isolation of structures has been studied rigorously as an approach to reduce seismic demand and mitigate structural damage. Research in this field has progressed significantly, starting from the use of simple elastomeric bearings for the decoupling of the superstructure from the base, to more complex devices that incorporate the use of an additional oscillating mass and negative stiffness elements. Characteristic examples of these devices are the Tuned Mass Damper (TMD) and the Quasi-Zero oscillators (QZSs). The KDamper is a novel passive vibration absorption concept, based essentially on the optimal combination of appropriate stiffness and mass elements, which include a negative stiffness element. The concept can be implemented using a system of prestressed elements in order to obtain the negative stiffness effects and might prove to achieve a significant advantage for seismic retrofitting.In this paper, the extended KDamper system is placed at the ground level and the soilstructure interaction (SSI) between the building foundations and superstructure is utilized as a means to effectively transfer the dynamic forces of the KDamper to the building and to distribute the required displacements between the structural elements and foundation, thus leading to absorption of the vibration energy. The configuration of the KDamper properties and tuning of its stiffness elements are studied herein. The effectiveness of the KDamper is subsequently investigated in view of the performance of a 4-storey building. A series of artificial accelerograms and real earthquake time histories are used as excitation. Results indicate the beneficial role of SSI on the reduction of the spectral acceleration and displacements, hence placing the concept as a compelling alternative to existing seismic protection technologies.

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“…It has been also tested as a vertical seismic absorber [50][51][52] and as a vibration control strategy of wind turbine towers [53,54]. Another variant of the KDamper, the SBA (Seismic Base Absorber), which consists of the EKD connected in parallel with an inerter element has also been investigated [55,56]. In [57], a novel design for the NS element of the SBA was proposed, the performance of the device was examined and an indicative placement in the base of a structure was suggested.…”

Section: Introductionmentioning

confidence: 99%

Design and Performance Assessment of Base Isolated Structures Supplemented with Vibration Control Systems

Sapountzakis,

Florakis,

Kapasakalis

2024

Buildings

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This paper investigates the implementation of supplemental vibration control systems (VCS) in base isolated (BI) structures, to improve their dynamic performance. More specifically, the aim of the VCS is to reduce the base displacement demand of BI structures, and at the same time mitigate the superstructure seismic responses. The purpose of the examined VCS is dual, and for this reason a multi-objective optimization methodology is formulated for the design of the VCS. The examined vibration absorbers include modifications of the KDamper concept. The KDamper is an extension of the traditional Tuned Mass Damper (TMD), and introduces a negative stiffness (NS) element to the additional oscillating mass of the TMD. The generated NS force is exactly in phase with the inertia force of the added mass, thus, artificially amplifying it. This way, lighter configurations are possible with an enhanced damping behavior. These VCS are designed based on engineering criteria and manufacturing constraints, while the excitation input used in the multi-objective optimization procedure is selected from a dataset of artificial accelerograms, designed to be spectrum-compatible with the EC8 design acceleration response spectrum. The effectiveness of the examined VCS is also assess with real near-fault earthquake records, and a comparison is performed with TMD-based VCS having 50 times larger additional masses. The numerical results demonstrate the superiority of the KDamper-based VCS in improving the dynamic behavior of BI structures over other mass-related systems (TMD).

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Seismic Protection of Multi-Story Structures With Novel Vibration Absorption Devices Combining Negative Stiffness and Inerter

Cited by 6 publications

References 0 publications

3d Numerical Investigation of an Extended Kdamper Absorber for Seismic Retrofitting of Low-Rise Buildings

3d Numerical Investigation of an Extended Kdamper Absorber for Seismic Retrofitting of Low-Rise Buildings

Advanced Negative Stiffness Vibration Absorbers Coupled With Soil-Structure Interaction for Seismic Protection of Buildings

Design and Performance Assessment of Base Isolated Structures Supplemented with Vibration Control Systems

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