Effect of Velocity Dependence on Sliding Characteristic of Sliding Types of Base Isolation Systems Each With Numerous Sliding Interfaces

2011 ◽  
Author(s):  
C. S. Tsai ◽  
H. C. Su ◽  
T. C. Chiang
Keyword(s):  
Base Isolation ◽  
Velocity Dependence ◽  
Analysis Software ◽  
Pendulum System ◽  
Sliding Interfaces ◽  
Velocity Effect ◽  
Isolation Systems ◽  
Friction Pendulum ◽  
The Given ◽  
Base Isolators

Current structural analysis software programs offer few if any applicable device-specific hysteresis rules or nonlinear elements considering the velocity effect on the mechanical behavior of the multiple friction pendulum system (MFPS) with numerous sliding interfaces. Based on the concept of subsystems, here we propose an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations to take into account the velocity dependence effect on the sliding behavior of the sliding interfaces in the sliding type base isolators. Evaluations of the velocity dependence effect on the features of the sliding motions on numerous sliding interfaces have also been carried out. Results from the given examples demonstrate that the sliding motions of sliding interfaces considering velocity dependence behave quite differently from those excluding the effect of velocity dependence.

scholarly journals THE INVESTIGATION BASE ISOLATOR IN CONTROLLING THE RESPONSE OF THE STRUCTURES DURING EARTHQUAKES

2018 ◽  
Vol 1 (18) ◽  
Author(s):  
Barghlame Hadi ◽  
Gavgani Hojjat Hashempour
Keyword(s):  
Base Isolation ◽  
Comparative Investigation ◽  
Pendulum System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Fixed Base ◽  
High Damping Rubber ◽  
Isolation Systems ◽  
Friction Pendulum ◽  
Base Isolators

Base isolation systems are among the most successful and widely applied methods of mitigatingstructural vibration and damage during seismic events. These systems have been installed in numerousfull-scale structures all around. There are three principal types of base isolators: Lead Rubber Bearing(LRB), High Damping Rubber Bearing (HDRB), and Friction Pendulum System (FPS). It is necessaryto extensively examine the response of different LRB isolators—by combining them with re-centeringand damping properties for isolated steel frame buildings experiencing several NF ground motions. Thepresent research uses comparative-descriptive methodology and application in terms of objectives. Thedata needed for the study were collected using library references and through reviewing related studiesconducted in the past in the same field.Results of the current comparative investigation indicated significant reductions in the storey drift,shear, and acceleration and increment in the storey displacement. According to the findings of thecurrent study, base isolators provide flexibility to massive structures against earthquakes. Thesestructures are situated on rigid soils. Moreover, base isolation was found to be the most effective incontrolling the response of the structures during earthquakes. Finally, shear, storey drift, and storeydisplacement reduce due to the use of base isolators as compared to the fixed-base structure.

The effects of input earthquake characteristics on the nonlinear dynamic behavior of FPS isolated liquid storage tanks

2016 ◽  
Vol 24 (7) ◽  
pp. 1264-1282 ◽  
Author(s):  
Saman Bagheri ◽  
Mostafa Farajian
Keyword(s):  
Passive Control ◽  
Base Isolation ◽  
Ground Motions ◽  
Storage Tanks ◽  
Ground Acceleration ◽  
Pendulum System ◽  
Aspect Ratios ◽  
Liquid Storage ◽  
Isolation Systems ◽  
Friction Pendulum

There are several methods to reduce the seismic damages in liquid storage tanks. One of these methods is to use passive control devices, in particular seismic base isolators. Among the different base isolation systems, the Friction Pendulum System (FPS) whose period does not depend on the weight of the system is more appropriate for isolation of liquid storage tanks. The aim of this paper is to investigate the effects of peak ground acceleration (PGA) and pulselike characteristics of earthquakes on the seismic behavior of steel liquid storage tanks base isolated by FPS bearings. In addition, impact effects of the slider with the side retainer are investigated, as well as effects of tank aspect ratio, isolation period and friction coefficient. The obtained results of tanks with different aspect ratios indicate that the responses get more reduced due to isolation under far-field ground motions compared to near-fault ground motions. It is also seen that the response of a base isolated tank is affected when contact takes place with the side retainer of the FPS.

Seismic Responses of a Building Isolated With Multiple Friction Pendulum System Subjected to Multi-Directional Excitations

2010 ◽  
Author(s):  
C. S. Tsai ◽  
Yung-Chang Lin ◽  
H. C. Su
Keyword(s):  
Base Isolation ◽  
Numerical Analyses ◽  
Good Tool ◽  
Isolation System ◽  
Pendulum System ◽  
Sliding Interfaces ◽  
Base Isolation System ◽  
Structural Responses ◽  
Friction Pendulum ◽  
Friction Pendulum System

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.

Multiple Yield and Bounding Surfaces Model for Analysis of Multiple Friction Pendulum System

2009 ◽  
Author(s):  
C. S. Tsai ◽  
Yung-Chang Lin ◽  
H.-C. Su
Keyword(s):  
Mechanical Characteristic ◽  
Isolation System ◽  
Pendulum System ◽  
Damping Effect ◽  
Proposed Model ◽  
Sliding Interfaces ◽  
In Series ◽  
Friction Pendulum ◽  
Bounding Surfaces ◽  
Friction Pendulum System

In order to systematically investigate the mechanical characteristic of a multiple friction pendulum system with more than two concave sliding interfaces and one articulated slider located between these concave sliding interfaces, on the basis of the plasticity theory, a plasticity model called the multiple yield and bounding surfaces model is proposed in addition to analytical formulations derived from the proposed concept of subsystems in this study. The proposed model has two separate groups of multiple yield and bounding surfaces. The first group is adopted to describe the mechanical behavior of the subsystem including the concave sliding interfaces above the articulated slider and the second group is used for modeling the sliding characteristic of the subsystem representing the concave sliding interfaces below the articulated slider. The connection of these two subsystems in series forms the mechanical characteristic of the entire MFPS isolation system. By virtue of the proposed model, the phenomena of the sliding motions of the MFPS isolator with multiple concave sliding interfaces under cyclical loadings can be clearly understood. Analytical results infer that the natural frequency and damping effect of the MFPS isolator with multiple concave sliding interfaces change continually during earthquakes and are controllable through appropriate designs.

Seismic Behavior of High-Tech Facility Isolated With a Trench Friction Pendulum System

2006 ◽  
Author(s):  
C. S. Tsai ◽  
Yung-Chang Lin ◽  
Wen-Shin Chen
Keyword(s):  
High Efficiency ◽  
Base Isolation ◽  
Good Choice ◽  
Earthquake Damage ◽  
Shaking Table ◽  
High Tech ◽  
Isolation System ◽  
Pendulum System ◽  
Friction Pendulum ◽  
Friction Pendulum System

Seismic mitigation of high-tech facilities is a very important issue in earthquake prone areas such as Taiwan, Japan, U.S.A., etc. In order to lessen vulnerability of earthquake damage of high-tech equipment, base isolation seems to be a good choice. This paper mainly explores the possibility of using a new base isolation system named the trench friction pendulum system (TFPS) to reduce seismic responses of high-tech facilities. The main reasons, from a engineer’s point of view, to use this system for protecting high-tech equipment from earthquake damage are high efficiency and low cost. A series of shaking table tests for a high-tech facility isolated with TFPS isolators were carried out in the Department of Civil Engineering, Feng Chia University, Taichung, Taiwan, ROC. The experimental results show that the proposed system provides a good protection for the high-tech facility during strong earthquakes.

Characteristics and Modeling of Multiple Direction Optimized-Friction Pendulum System With Numerous Sliding Interfaces Subjected to Multidirectional Excitations

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
C. S. Tsai ◽  
H. C. Su ◽  
Yung-Chang Lin
Keyword(s):  
Simple Manner ◽  
Natural Period ◽  
Pendulum System ◽  
Damping Effect ◽  
Proposed Model ◽  
Base Isolator ◽  
Sliding Interfaces ◽  
Friction Pendulum ◽  
Bounding Surfaces ◽  
Friction Pendulum System

In this paper, a base isolator called a multiple direction optimized-friction pendulum system (Multiple DO-FPS) with numerous sliding interfaces is proposed. To understand the mechanical behavior of the Multiple DO-FPS isolator under multidirectional excitations, an analytical model called the multiple yield and bounding surfaces model is proposed. On the basis of the derived mathematical formulations for simulation of the characteristics of the Multiple DO-FPS isolation bearing, it is revealed that the natural period and damping effect of the Multiple DO-FPS isolator are a function of the sliding displacement and sliding direction. By virtue of the proposed model, the phenomena of the sliding motions of the Multiple DO-FPS isolator with numerous sliding interfaces subjected to multidirectional excitations can be understood in a simple manner. The analytical results indicate that the natural frequency and damping effect of the Multiple DO-FPS isolator with numerous concave sliding interfaces change continually during earthquakes and are controllable through appropriate designs.

Characteristic and Modeling of Multiple Direction Optimized-Friction Pendulum System With Numerous Sliding Interfaces Subjected to Multi-Directional Excitations

2010 ◽  
Author(s):  
C. S. Tsai ◽  
Yung-Chang Lin ◽  
H.-C. Su
Keyword(s):  
Natural Period ◽  
Pendulum System ◽  
Damping Effect ◽  
Sliding Direction ◽  
Proposed Model ◽  
Base Isolator ◽  
Sliding Interfaces ◽  
Friction Pendulum ◽  
Bounding Surfaces ◽  
Friction Pendulum System

In this paper, a base isolator call the multiple direction optimized-friction pendulum system (Multiple DO-FPS) with numerous sliding interfaces is proposed. For understanding the mechanical behavior of the Multiple DO-PFS isolator under multi-directional excitations, an analytical model called the multiple yield and bounding surfaces model is also proposed. On the basis of the derived mathematical formulations for the simulation of the characteristic of the Multiple DO-FPS isolation bearing, it is revealed that the natural period and damping effect for a Multiple DO-FPS is a function of the sliding displacement and sliding direction. By virtue of the proposed model, the phenomena of the sliding motions of the Multiple DO-FPS isolator with numerous sliding interfaces subjected to multi-directional excitations can be simply understood. Analytical results infer that the natural frequency and damping effect of the Multiple DO-PFS isolator with numerous concave sliding interfaces change continually during earthquakes and are controllable through appropriate designs.

Seismic Isolation Retrofit of an Office Building Using Friction Pendulum System

2014 ◽  
Vol 578-579 ◽  
pp. 1361-1365
Author(s):  
Lin Liu ◽  
Xuan Min Li ◽  
Wei Tian
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Time History ◽  
Nonlinear Behavior ◽  
Office Building ◽  
Nonlinear Time History Analysis ◽  
Isolation System ◽  
Pendulum System ◽  
Nonlinear Time History ◽  
Friction Pendulum

Friction Pendulum Systems have been used as base isolation systems for both new construction and retrofit around the world. This paper presented its implementation in an office building located in Shanghai. To evaluate its impact on seismic performance of the retrofitted structure, models are needed to capture the intricate nonlinear behavior of both structural components and isolator elements. Nonlinear time history analysis of the building for the original and retrofitted cases was conducted to assess the efficiency of the isolation system at the high earthquake level. The numerical results indicate that the retrofitted structure experiences significantly less damage and less deformation due to the shake isolation and energy dissipation through the isolators.

scholarly journals Performance Analysis and Comparison of Two Base Isolation Systems with Super-Large Displacement Friction Pendulum Bearings

2020 ◽  
Vol 10 (22) ◽  
pp. 8235
Author(s):  
Peisong Wu ◽  
Jinping Ou
Keyword(s):  
Seismic Performance ◽  
Base Isolation ◽  
Design Method ◽  
Horizontal Displacement ◽  
Large Displacement ◽  
Large Radius ◽  
Isolation Layer ◽  
Deformation Ability ◽  
Isolation Systems ◽  
Friction Pendulum

Isolation technology has been successfully applied in seismic migration. With increasing of seismic demand, seismic performance of isolation structures subjected to very-rare earthquakes need further improvement. However, the isolation layer generally lacks sufficient deformation ability under very-rare earthquakes due to the deformation limit of classical isolation bearing. In order to circumvent the difficulty, this paper develops two new isolation bearings, namely super-large displacement rotation friction pendulum bearing (SLDRFPB) and super-large displacement translation friction pendulum bearing (SLDTFPB). By setting spherical shells with large span and large radius, large horizontal displacement and small horizontal stiffness can be achieved. Safety of the isolation layer and the isolation effect of the superstructure can be greatly improved. SLDTFPB differs from SLDRFPB in the motion state of the superstructure and space utilization of the isolation layer, thus SLDRFPB and SLDTFPB are suitable for structures with different requirements. Due to rotation of the superstructure with SLDRFPB or sliding frames in SLDTFPB, the traditional design method of friction pendulum bearing is no longer suitable. We present a new procedure to accurately and conveniently evaluate seismic performance of two developed bearings. Numerical simulation shows that the seismic response of both the superstructure and isolation layer is small. Developed SLDRFPB and SLDTFPB have sufficient emergency capacity and isolation resilience when subjected to very-rare earthquakes.

Experimental Study of a Full Scale Building Isolated With Multiple Friction Pendulum System With Multiple Sliding Interfaces

2011 ◽  
Author(s):  
C. S. Tsai ◽  
Y. M. Wang ◽  
H. C. Su
Keyword(s):  
Full Scale ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Pendulum System ◽  
Residual Displacements ◽  
Fixed Base ◽  
Sliding Interfaces ◽  
Friction Pendulum ◽  
Base Structure ◽  
Friction Pendulum System

Presented in this paper is the performance evaluation of the multiple friction pendulum system (MFPS) with multiple sliding interfaces on seismic mitigation through a series of shaking table tests of a full scale MFPS-isolated building. In the tests, a three-story steel building of 40 tons in total weight, 3m and 4.5m in two horizontal directions and 9m in height, was equipped with MFPS isolators each with 4 sliding interfaces and subjected to various types of earthquakes to examine the efficiency of the isolators in reducing seismic response of a structure. Experimental results from shaking table tests tells that the roof accelerations, base shears, column shear forces have been significantly lessened with negligible residual displacements in the isolators while compared to the responses of a fixed-base structure.

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