A Highly Adjustable Base Isolator Utilizing Magnetorheological Elastomer: Experimental Testing and Modeling

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Yancheng Li ◽  
Jianchun Li
Keyword(s):  
Analytical Model ◽  
Structural Control ◽  
Seismic Isolation ◽  
Experimental Testing ◽  
Lateral Stiffness ◽  
Magnetorheological Elastomer ◽  
Civil Structures ◽  
Isolation System ◽  
Base Isolator ◽  
Research Advance

This paper presents a recent research advance on the development of a novel adaptive seismic isolation system to be used in seismic protection of civil structures. A highly adjustable laminated magnetorheological elastomer (MRE) base isolator was developed and experimental results show that the prototypical MRE base isolator provides increase in lateral stiffness up to 1630%. To facilitate the structural control development using such adaptive MRE base isolator, an analytical model was developed to simulate its behaviors. Comparison between the analytical model and experimental data proves the effectiveness of such model in reproducing the behavior of MRE base isolator.

Development and Modeling of a Highly-Adjustable Base Isolator Utilizing Magnetorheological Elastomer

2013 ◽  
Author(s):  
Yancheng Li ◽  
Jianchun Li
Keyword(s):  
Analytical Model ◽  
Seismic Isolation ◽  
Large Scale ◽  
Lateral Stiffness ◽  
Magnetorheological Elastomer ◽  
Isolation System ◽  
Vertical Loading ◽  
Base Isolator ◽  
Field Dependent ◽  
Dependent Property

This paper presents a recent research breakthrough on the development of a novel adaptive seismic isolation system as the quest for seismic protection for civil structures, utilizing the field-dependent property of the magnetorheological elastomer (MRE). A highly-adjustable MRE base isolator was developed as the key element to form smart seismic isolation system. The novel isolator contains unique laminated structure of steel and MRE layers, which enable its large-scale civil engineering applications, and a solenoid to provide sufficient and uniform magnetic field for energizing the field-dependent property of MR elastomers. With the controllable shear modulus/damping of the MR elastomer, the developed adaptive base isolator possesses a controllable lateral stiffness while maintaining adequate vertical loading capacity. Experimental results show that the prototypical MRE base isolator provides amazing increase of lateral stiffness up to 1630%. Such range of increase of the controllable stiffness of the base isolator makes it highly practical for developing new adaptive base isolation system utilizing either semi-active or smart passive controls. To facilitate the structural control development using the adaptive MRE base isolator, an analytical model was developed to stimulate its behaviors. Comparison between the analytical model and experimental data proves the effectiveness of such model in reproducing the behavior of MRE base isolator, including the observed strain stiffening effect.

Study on Characteristics and Effects of Seismic Isolation System of Vertically Utilized Coiled Springs

2007 ◽  
Author(s):  
Tsuyoshi Fukasawa ◽  
Akihiro Kinoshita ◽  
Satoshi Fujita
Keyword(s):  
Analytical Model ◽  
Seismic Isolation ◽  
304 Stainless Steel ◽  
Restoring Force ◽  
Isolation System ◽  
Static Tests ◽  
Coiled Spring ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Isolation Performance

In recent years many structures employing seismic isolation systems have been constructed in Japan, the practical concern on the cost of seismic isolation systems has heightened. This paper describes the research and development of a new seismic isolation system using vertically utilized elastic and elasto-plastic coiled spring, and discusses analytical model for coiled spring. The basic concept of the earthquake isolation system that was constituted of bearing, restoration and damping elements is to realize cost effective design without any reduction in isolation performance. The restoration and damping elements of the isolation system were constituted by two types of coiled springs. The horizontal static tests were performed to evaluate the restoring characteristic and the mechanical model of elastic and elasto-plastic coiled spring. The restoration element of elastic coiled springs was made of using the two types of materials JIS SUP9 steel and JIS SUS 304 stainless steel. The elasto-plastic coiled springs of damping element also was made of using the two types of JIS SS 400 steel and JIS SWRM 17 steel. The characteristics of these coiled springs such as transverse stiffness and hysteretic damping and the validity of the analytical model were clarified through the static tests. Furthermore the response analyses based on the restoring force characteristics of experimental results were carried out to assess the isolation performance of this system.

scholarly journals Kajian Respon Bangunan Menggunakan Base Isolator pada Gedung Bertingkat Sistem Pracetak dan Sistem Cast in Situ. (Hal. 50-61)

2019 ◽  
Vol 5 (1) ◽  
pp. 50
Author(s):  
Ardiansyah Ibrahim ◽  
Erma Desmaliana ◽  
Amatulhay Pribadi
Keyword(s):  
Shear Force ◽  
Seismic Isolation ◽  
Precast Concrete ◽  
Isolation System ◽  
Tectonic Plates ◽  
Rubber Bearing ◽  
High Damping Rubber Bearing ◽  
Base Isolator ◽  
High Damping Rubber

ABSTRAKIndonesia merupakan wilayah yang memiliki resiko gempa yang cukup tinggi karena terletak pada pertemuan tiga lempeng tektonik,oleh karena itu telah dikembangkan metode desain alternatif dengan tujuan untuk mengurangi resiko kerusakan bangunan akibat beban gempa yang dikenal dengan nama sistem isolasi gempa (seismic isolation).Pada bangunan ini dipasang base isolator jenis High Damping Rubber Bearing (HDRB) dengan diameter 600 mm dan tinggi 407,9 mm.Berdasarkan hasil, diperoleh bahwa penggunaan base isolator dapat memperpanjang periode struktur bangunan dua kali untuk kedua sistem, kemudian dapat mereduksi gaya geser arah X mencapai 40% dan arah Y mencapai 50% untuk kedua sistem, lalu memperkecil simpangan antar lantai dan juga membutuhkan waktu yang lebih singkat untuk mencapai faktor partisipasi modal yang diinginkan sesuai peraturan yaitu minimal 90%. Kesimpulan dari penelitian ini adalah struktur bangunan beton pracetak lebih efektif dibandingkan dengan beton cast in situ dari aspek respon struktur.Kata kunci: pracetak, cast in situ, high damping rubber bearing ABSTRACTIndonesia is prone to seismic hazard load due to its location situated on a meeting point of three tectonic plates, therefore the alternative design methods have been developed with the aim to reduce the risk of damage to buildings due to the load known as the earthquake isolation system. At one of the building analyzed in this research was provided with High Damping Rubber Bearing (HDRB) with a diameter of 600 mm and a height of 407,9 mm. Based on the results obtained, the use of base isolator can extend the period of the structure of the building twice forboth systems, reduce the shear force reached 40% in the X direction and 50% in the Y direction for both systems, and then minimize the deviation between floors of a building and also requires less time to achieve the desired modal participation factors according the regulations that is at least 90%. The conclusion of this research is that the structure of precast concrete is more effective than cast in situ concrete from the aspect of structure response.Keywords: precast, cast in situ, high damping rubber bearing

Isolation Performance of Intelligent Seismic Isolation System Using Air Bearing

2009 ◽  
Author(s):  
Satoshi Fujita ◽  
Keisuke Minagawa ◽  
Mitsuru Miyazaki ◽  
Go Tanaka ◽  
Toshio Omi ◽  
...  
Keyword(s):  
Seismic Isolation ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Vertical Motion ◽  
Air Bearings ◽  
Natural Period ◽  
Isolation System ◽  
Vertical Excitation ◽  
Long Period ◽  
Isolation Performance

This paper describes three-dimensional isolation performance of seismic isolation system using air bearings. Long period seismic waves having predominant period of from a few seconds to a few ten seconds have recently been observed in various earthquakes. Also resonances of high-rise buildings and sloshing of petroleum tanks in consequence of long period seismic waves have been reported. Therefore the isolation systems having very long natural period or no natural period are required. In a previous paper [1], we proposed an isolation system having no natural period by using air bearings. Additionally we have already reported an introduction of the system, and have investigated horizontal motion during earthquake in the previous paper. It was confirmed by horizontal vibration experiment and simulation in the previous paper that the proposed system had good performance of isolation. However vertical motion should be investigated, because vertical motion varies horizontal frictional force. Therefore this paper describes investigation regarding vertical motion of the proposed system by experiment. At first, a vertical excitation test of the system is carried out so as to investigate vertical dynamic property. Then a three-dimensional vibration test using seismic waves is carried out so as to investigate performance of isolation against three-dimensional seismic waves.

scholarly journals Dynamic Characteristics of the Bouc–Wen Nonlinear Isolation System

2021 ◽  
Vol 11 (13) ◽  
pp. 6106
Author(s):  
Zhiying Zhang ◽  
Xin Tian ◽  
Xin Ge
Keyword(s):  
Dynamic Characteristics ◽  
Seismic Isolation ◽  
Influence Factors ◽  
Harmonic Balance Method ◽  
Control Parameters ◽  
Hysteretic Model ◽  
Incremental Harmonic Balance Method ◽  
Isolation System ◽  
Nonlinear Dynamic Characteristics ◽  
Incremental Harmonic Balance

The Bouc–Wen nonlinear hysteretic model has many control parameters, which has been widely used in the field of seismic isolation. The isolation layer is the most important part of the isolation system, which can be effectively simulated by the Bouc–Wen model, and the isolation system can reflect different dynamic characteristics under different control parameters. Therefore, this paper mainly studies and analyzes the nonlinear dynamic characteristics of the isolation system under different influence factors based on the incremental harmonic balance method, which can provide the basis for the dynamic design of the isolation system.

Vulnerability-Based Design of Sliding Concave Bearings for the Seismic Isolation of Steel Storage Tanks

2016 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci ◽  
Silvia Alessandri ◽  
Phuong Hoa Hoang
Keyword(s):  
Liquid Steel ◽  
Seismic Isolation ◽  
Failure Modes ◽  
Fragility Curves ◽  
Time History ◽  
Probability Of Failure ◽  
Design Parameters ◽  
Economic Losses ◽  
Storage Tanks ◽  
Isolation System

Liquid steel storage tanks are strategic structures for industrial facilities and have been widely used both in nuclear and non-nuclear power plants. Typical damage to tanks occurred during past earthquakes such as cracking at the bottom plate, elastic or elastoplastic buckling of the tank wall, failure of the ground anchorage system, and sloshing damage around the roof, etc. Due to their potential and substantial economic losses as well as environmental hazards, implementations of seismic isolation and energy dissipation systems have been recently extended to liquid storage tanks. Although the benefits of seismic isolation systems have been well known in reducing seismic demands of tanks; however, these benefits have been rarely investigated in literature in terms of reduction in the probability of failure. In this paper, A vulnerability-based design approach of a sliding concave bearing system for an existing elevated liquid steel storage tank is presented by evaluating the probability of exceeding specific limit states. Firstly, nonlinear time history analyses of a three-dimensional stick model for the examined case study are performed using a set of ground motion records. Fragility curves of different failure modes of the tank are then obtained by the well-known cloud method. In the following, a seismic isolation system based on concave sliding bearings is proposed. The effectiveness of the isolation system in mitigating the seismic response of the tank is investigated by means of fragility curves. Finally, an optimization of design parameters for sliding concave bearings is determined based on the reduction of the tank vulnerability or the probability of failure.

Development and Application of Innovative Anti-Seismic Systems for the Protection of Cultural Heritage: New Achievements of ENEA

2002 ◽  
Author(s):  
M. Indirli ◽  
M. Forni ◽  
A. Martelli ◽  
B. Spadoni ◽  
A. Dusi ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Seismic Isolation ◽  
New Technology ◽  
Three Dimensional ◽  
Ambient Vibration ◽  
Civil Structures ◽  
Industrial Plants ◽  
Marche Region ◽  
Passive Devices ◽  
New Development

As described in detail at previous ASME-PVP Conferences and also reminded by separate papers presented this year, large efforts have been devoted by the Italian Agency for New Technology, Energy and the Environment (ENEA), with the cooperation of several further members of the Italian Working Group on Seismic Isolation (GLIS), to the development, validation and application of innovative anti-seismic (IAS) techniques since 1988. To date, considered have been base and floor seismic isolation (SI), energy dissipation through various types of passive devices, hydraulic coupling by means of innovative shock transmitters, systems formed by shape memory alloy devices and more recently, semi-active control of vibrations. New activities at ENEA, which are in progress in the framework of both international and national collaborations, concern the development of new IAS techniques of the aforesaid kinds to be applied to: • civil structures and industrial plants; • cultural heritage structures (CUHESs) to be restored or reconstructed, or masterpieces to be seismically protected. Progress of the work performed for civil and industrial structures has been separately presented at this Conference, while this paper deals with the new development, validation and application activities concerning the IAS techniques applicable to the seismic protection of CUHESs, to which particular attention has been devoted by ENEA for several years. The ongoing activities for CUHESs are being performed in the framework of: • PROSEESM, a national project which foresees pilot applications of the IAS techniques to the restoration of CUHESs damaged by the 1997–98 Marche and Umbria earthquakes; • a feasibilily study for the reconstruction in the original site, with SI and the original masonry materials, of Mevale di Visso, a village in the Marche Region destroyed by the aforesaid event; • a study for the design and application of an innovative three-dimensional SI system for seismic and ambient vibration protection of a roman ship excavated at Ercolano, near Naples.

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