scholarly journals Performance of 2-D Frame Equipped With Base isolation System under Dynamic Loadings

2020 ◽  
Vol 184 ◽  
pp. 01099
Author(s):  
N. Omprakash Reddy ◽  
A. Manchalwar

Building responses have become a major concern in design research. Passive control techniques are implemented to improve structure efficiency. The present research aims to assess the efficiency of base isolation system for a 2D frame and to enhance the performance of structures that are subjected to seismic ground excitations and ground vibrations induced by blast. Two moments of resistant RC frames were studied and output of the isolator (Lead / Rubber Bearing) was observed to reduce structural responses. In SAP2000 non-linear dynamic analysis is conducted to compare normal and irregular moment-resistant frames and structural responses with and without passive control techniques. Isolators are constructed based on time of isolation. Reduction of structural responses is assessed by passive control techniques, and comparative analysis is performed. Mitigating systemic retaliation is affected by the implementation of passive control system.

2020 ◽  
Vol 6 (2) ◽  
pp. 52
Author(s):  
Muhammet Yurdakul ◽  
Mehmet Burak Yıldız

Base isolation system with lead rubber bearing (LRB) is commonly used to prevent structure against to damage of earthquake. Design of LRB system is detailed in this study. The isolated building with LRB design according to Uniform Building Code (UBC-97) and fixed building were examined. The six-storey building with LRB and fixed building were modelled in SAP2000 with the same dynamic loads. The relative floor displacement and internal forces of the seismic isolated and fixed building are compared. In addition, transverse and longitudinal reinforcement of any axis of seismic isolated and fixed building are compared. Analyse results showed that effectiveness of using seismic isolation system on building. The weight of longitudinal and transverse reinforcement of isolated building is smaller than fixed building about 36%, 40% respectively.


2012 ◽  
Vol 256-259 ◽  
pp. 2185-2192
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis ◽  
Mario Pasquino

In this paper a new seismic base isolator, called High Damping Hybrid Seismic Isolator (HDHSI), is proposed. It is obtained by the assembly in series of a Lead Rubber Bearing (LRB) and a Friction Slider (FS) with a high friction coefficient. The HDHSI device is in contrast with the Resilient-Friction Base Isolator (R-FBI) with the aim of optimizing the Electricité De France (EDF) system. The mathematical model of a structure base isolated by a HDHSI system is analyzed with a two Degree of Freedom System (2-DOF) in which the superstructure is assimilated to a rigid body. Nonlinear finite elements are adopted for modeling the HDHSI device. A dynamic nonlinear analysis is performed and the hysteretic cycles are derived and evaluated for the single components and for the innovative HDHSI device.


2020 ◽  
Vol 30 (3) ◽  
pp. 134-160
Author(s):  
Kuppalli Krishne Gowda Kiran ◽  
Ehsan Noroozinejad Farsangi

Abstract Unpredictable threat and danger may occur in a structural system due to blast loading. Long-span spatial structures are very practical and common in airport terminals, exhibition centers, stadiums, and other public buildings. For high-rise and multi-story structures, horizontal pressure plays a major role in the level of damage to a structure, whereas long-span structures may be influenced by both horizontal and vertical pressure. In the current study, the applicability of lead rubber bearing (LRB) has been evaluated on a low-rise, long-span structure. The analysis is carried out by using the MATLAB Simulink platform. The simulation results indicate that the base isolation system which is usually adopted for seismic control of structures can adequately reduce the structural responses under blast loadings.


2012 ◽  
Vol 166-169 ◽  
pp. 2513-2516
Author(s):  
Wei Qing Fu ◽  
Fei Chen ◽  
Hong Mei Wang

Rubber bearing base-isolation is well-developed vibration reduction technique, and is applied in practical engineering broadly. But displacement of vibration isolating layer is large, so lead plug rubber bearing is used. It is passive control device; therefore its optimal central extent is narrow. That is isolating layer is optical in several defined kind and magnitude of earthquake waves, in the way controlled displacement and acceleration of superstructure is ideal. Magnetorheological damper has good smart performances- broad controlled band, fast response and demand a little energy. In this paper smart base isolation system, which is combined with rubber bearing and MR damper, is applied to structural vibration control, and have numerical simulation of structure employing LRB isolation and smart isolation in different kind and magnitude of earthquake waves. The result indicates smart base-isolation with MR damper can supply optimal control to these different earthquake waves, so is a good supplement and perfection for former isolation technique.


2020 ◽  
Vol 6 (2) ◽  
pp. 181-194
Author(s):  
Syahnandito ◽  
Reni Suryanita ◽  
Ridwan

Salah satu cara yang dapat dilakukan adalah menggunakan peredam beban gempa dengan sistem isolasi dasar (base isolation system). Penggunaan base isolation system  pada bangunan dapat mengisolasi perambatan getaran akibat gempa dari tanah ke struktur atas bangunan menggunakan komponen berbahan karet. Tujuan penelitian ini adalah untuk menganalisis pengaruh penggunaan sistem isolasi dasar berupa High Damping Rubber Bearing pada periode dan gaya geser dasar  struktur beton bertulang. Objek penelitian adalah bangunan hotel 15 lantai dengan ketinggian 62,9 m. Penelitian diawali dengan pemodelan struktur menggunakan aplikasi ETABS v2016 sehingga didapatkan periode dan gaya geser dasar struktur fixbase. Tahap selanjutnya memberikan gaya pada model struktur dengan isolasi dasar High Dumper Rubber Bearing sehingga didapatkan periode dan gaya geser dasar struktur dengan base isolator. Hasil analisis pada struktur fixbase didapatkan periode sebesar 4,212 detik, dengan gaya geser dasar didapatkan sebesar 1470,725 ton. Sedangkan hasil analisis pada struktur dengan base isolator didapatkan periode sebesar 5,500 detik, dengan gaya geser dasar didapatkan sebesar 1286,071 ton. Maka dapat disimpulkan bahwa pada struktur dengan base isolator terjadi peningkatan periode sebesar 30,58 %, sedangkan gaya geser dasar terjadi penurunan 12,56 %.


Author(s):  
C. S. Tsai ◽  
Yung-Chang Lin ◽  
H. C. Su

In order to prevent a building from earthquake damage, a base isolation system called the multiple friction pendulum system (MFPS) which has numerous concave sliding interfaces is proposed to isolate a building from its foundation. Mathematical formulations have been derived to simulate the characteristic of the MFPS isolation system subjected to multi-directional excitations. By virtue of the derived mathematical formulations, the phenomena of the sliding motions of the MFPS isolator with several concave sliding interfaces under multi-directional earthquakes can be clearly understood. Also, numerical analyses of a building isolated with the MFPS isolator with several sliding interfaces have been conducted in this study to evaluate the efficiency of the proposed system in seismic mitigation. It has been proved through numerical analyses that structural responses have been reduced significantly and that the proposed system is a good tool to insure the safety of structures during earthquakes.


Author(s):  
Krzysztof Wilde ◽  
Paolo Gardoni ◽  
Yozo Fujino ◽  
Stefano Besseghini

Abstract Base isolation provides a very effective passive method of protecting the structure from the hazards of earthquakes. The proposed isolation system combines the laminated rubber bearing with the device made of shape memory alloy (SMA). The smart base isolation uses hysteretic behavior of SMA to increase the structural damping of the structure and utilizes the different responses of the SMA at different levels of strain to control the displacements of the base isolation system at various excitation levels. The performance of the smart base isolation is compared with the performance of isolation by laminated rubber bearings to assess the benefits of additional SMA damper for isolation of three story building.


2013 ◽  
Vol 831 ◽  
pp. 110-114
Author(s):  
S. Alvandi ◽  
M. Ghassemieh

Seismic isolation system is an example of passive control system that effectively improves the performance of structures. This research discusses the seismic performance of a elastomeric base isolation system which provide the combined features of vertical load support, horizontal flexibility and energy absorbing capacity, utilizing shape memory alloys that provides re-centering force and additional damping in the system. Also this paper compares the effect of such alloys with memory effect and/or superelasticity (with pre-straining) in base isolated structure. To provide such comparison, a nonlinear structural model has been developed on some benchmark control problems and some health monitoring evaluation criterias are used. The smart base isolation utilizes the different responses of shape memory alloys at several levels of strain to control the displacements of the rubber bearing and base shear at excitation level. Furthermore the proposed based isolation systems has enhanced performance in terms of response reduction and re-centering capacity.


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