Seismic response of torsionally coupled building with passive and semi-active stiffness dampers

Abstract

The seismic response of single-storey, oneway asymmetric building with passive and semi-active variable stiffness dampers is investigated. The governing equations of motion are derived based on the mathematical model of asymmetric building. The seismic response of the system is obtained by numerically solving the equations of motion using state-space method under different system parameters. The switching and resetting control laws are considered for the semi-active devices. The important parameters considered are eccentricity ratio of superstructure, uncoupled lateral time period and ratio of uncoupled torsional to lateral frequency. The effects of these parameters are investigated on peak lateral, torsional and edge displacements and accelerations as well as on damper control forces. The comparative performance is investigated for asymmetric building installed with passive stiffness and semi-active stiffness dampers. It is shown that the semi-active stiffness dampers reduce the earthquake-induced displacements and accelerations significantly as compared to passive stiffness dampers. Also, the effects of torsional coupling on effectiveness of passive dampers in reducing displacements and accelerations are found to be more significant to the variation of eccentricity as compared to semi-active stiffness dampers.

Identification of Torsionally Coupled Shear Buildings Models Using a Vector Parameterization

“…The next values of damping are recommended, 1-2% for steel buildings and 3-5% for reinforced concrete buildings [18]. This assumption allows computing the parameters 0 and 1 in (14) and (15) as follows: Define the following vectors:…”

“…The parameter identification of torsionally coupled shear building models has been a topic of interest in the last three decades [1][2][3][4][5][6][7][8][9][10][11][12][13]. Its identification is important because it allows verifying the structural health, or designing control law techniques that attenuate the vibration of the building when it is excited by external forces as earthquakes or wind [14][15][16]. This kind of model more closely approximates a shear building than the planar frame model, which is widely used in the literature [17][18][19].…”

Effects and distribution of semi‐active resettable springs on the seismic response of asymmetric structures

“…The most common semi‐active device studied by researchers are magnetorheological (MR) dampers. Several control algorithms have also been introduced to better provide control of the seismic response of asymmetric structures 15–17 . In contrast with MR dampers, semi‐active resettable springs (SRSs) 18,19 have shown superior performance.…”

Resetting passive stiffness damper with passive negative stiffness device for seismic protection of structures

“…The resetting semi‐active stiffness damper (RSASD) has been studied extensively for seismic protection of structures, where its effectiveness has been demonstrated for both buildings and bridges in the presence of near‐field earthquake ground motions 1–20 . This has motivated recent research into an improved damper configuration where all the semi‐active components were replaced by a simple mechanism for achieving resetting of the damper force 21 .…”