Novel Displacement Dependent Viscous Damper for Semiactive Control of the Seismic Response of Multistorey Buildings


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Kiral A., Petkovski M.

Diğer, ss.1-120, 2022

  • Yayın Türü: Diğer Yayınlar / Diğer
  • Basım Tarihi: 2022
  • Sayfa Sayıları: ss.1-120
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

Semiactive (SA) control devices offer significant advantages over passive devices for control of the seismic response of multistorey buildings, but the currently proposed systems suffer from high complexity, leading to increased response lags and concerns about their robustness. An ideal semiactive control should be simple, offering fast response and sufficient control forces while limiting the storey shear and the deformations of the building. Friction based SA systems offer large control forces but are slow and require high energy input. Viscous fluid dampers, which are the focus of this study, offer fast response with very small energy requirements, but introduce difficulties in controlling the maximum storey shear.  This study builds on a recently proposed semiactive control system (2-4DDD: Direction and Displacement Dependent) based on fluid viscous dampers in which the damper forces are controlled by the deformations of the structure (storey drift). This means that the aim of the semiactive control is to maintain a predefined relationship between the damper force and the storey drift.  This study first assesses the performance of 2-4DDD when applied in a realistic scenario of earthquake response of two typical multistorey moment resisting frames (low- and medium-rise buildings) equipped with fluid viscous dampers installed in a Chevron brace configuration and subjected to 5 recorded strong earthquakes with different predominant frequency ranges. Unlike all previous research, in which the SA systems were applied to simplified, linear-elastic MDOF systems, this investigation is carried out by the means of time history simulations of nonlinear response, including development of plastic hinges in the main structure. Performance is assessed by evaluating story drift, which is directly associated with structural damage, and total base-shear which is a measure of the risk of ground floor failure.  The study then introduces two new SA control algorithms designed to control the shape of the structural hysteresis (the relationship between storey shear and inter-storey drift): 2-4DVD (Displacement and Velocity Dependent) and 2-4VDD (Velocity and Displacement Dependent); and a design methodology for the vertical distribution of control parameters for each system. Their performance is again assessed by non-linear time history simulations. The results of the new SA system 2-4DVD, compared with a passive non-linear viscous damper (PNLV) and the existing 2-4DDD viscous damper, show that the new control algorithm is (i) more effective than both in terms of reduced displacement (for the same or less total base shear), and (ii) more robust over a range of ground motions than the 2-4DDD. The 2-4VDD, introduced as a potential improvement in the total base shear of 24DVD control, produced lower maximum total base shear by 20-26%, but with significantly increased maximum damper forces (up to over 80%); and can be used in cases where the base shear in the main structure is critical.