A negative stiffness dynamic base absorber for seismic retrofitting of residential buildings

Abstract

In this study, a negative stiffness-based passive vibration absorber is developed and implemented as a seismic retrofitting measure for typical reinforced concrete (RC) residential buildings. The device, namely, the extended KDamper for retrofitting (EKD-R), is introduced at the base of the structure, between the foundation level and the first story of the building. The design of the EKD-R device and the selection of its properties are undertaken by incorporating a harmony search (HS) algorithm that provides optimized parameters for the mechanism, following constraints and limitations imposed by the examined structural system. Nonlinearities due to the plastic behavior of the structural members and soil-structure interaction (SSI) effects are modeled and taken into consideration during the process. Subsequently, a realistic case study of a benchmark three-story RC building is examined, and the performance of the EKD-R system is assessed. The building superstructure is designed according to Eurocodes. The structure-foundation system, along with the EKD-R, is explicitly modeled using finite elements (FE) that may realistically capture structural nonlinearities and SSI effects. The HS algorithm is employed, and optimized EKD-R components are obtained and implemented in the benchmark structure. Finally, a series of recorded real ground motions are selected, and nonlinear time-history dynamic analyses are conducted aiming to assess the behavior of the controlled system. Results indicate the beneficial role of the novel dynamic absorber, hence rendering the concept a compelling seismic retrofitting technology.

A Damage Index for Assessing Seismic-Resistant Designs of Masonry Wall Buildings Reinforced with X-Bracing Concrete Frames

“…Then, the monotonic loading and cyclic loading characteristics of the deformed samples are analysed by defining displacement control according to the force pattern used to test each sample. Figure 2 shows a sample that defines the displacement value in the model [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Then, the analysis results are used to calculate and determine a suitable coefficient and damage index.…”

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

“…It is differentiated from the initial design due to: (i) the placement of the NS element between the isolation level and the additional mass and (ii) the installation of an extra artificial damper parallel to the NS element. The performance of the EKD in providing horizontal seismic protection for buildings has been studied in [47,48] and an indicative design of the device was conducted in [49]. 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].…”

On the Vibration Attenuation Performance of a Geometrically Nonlinear Device Mounted to a Multi-Storey Structure

“…Nonlinearity and negative stiffness have also been studied in metamaterial configurations [11,12,13,14], demonstrating potential towards structural applications of [15,16] within the metabarrier and metafoundation context. Within the context of geometrically nonlinear mechanisms targeting a negative stiffness effect, the K-Damper device has been recently proposed [17,18,19]. This incorporates a negative stiffness element, which increases the channelling of energy to a secondary attachment.…”