Parametric Study of SMA-based Friction Pendulum System for Response Control of Bridges under Near-Fault Ground Motions

2019 ◽  
pp. 1-19 ◽  
Author(s):  
Wen-Zhi Zheng ◽  
Hao Wang ◽  
Jian Li ◽  
Hui-Jun Shen
Keyword(s):  
Parametric Study ◽  
Ground Motions ◽  
Response Control ◽  
Pendulum System ◽  
Near Fault ◽  
Friction Pendulum ◽  
Friction Pendulum System

Finite Element Formulations and Theoretical Study for VCFPS

2003 ◽  
Author(s):  
C. S. Tsai ◽  
Tsu-Cheng Chiang ◽  
Bo-Jen Chen
Keyword(s):  
Finite Element ◽  
Base Isolation ◽  
Ground Motions ◽  
Base Shear ◽  
Pendulum System ◽  
Near Fault ◽  
Base Isolator ◽  
Friction Pendulum ◽  
Finite Element Formulations ◽  
Friction Pendulum System

The friction pendulum system (FPS), a type of base isolation technology, has been recognized as a very efficient tool for controlling the seismic response of a structure during an earthquake. However, previous studies have focused mainly on the seismic behavior of base-isolated structures far from active earthquake faults. In recent years, there have been significant studies on the efficiency of the base isolator when subjected to near-fault ground motions. It is suggested from these studies that the long-duration pulse of near-fault ground motions results in significant response of a base-isolated structure. In view of this, an advanced base isolator called the variable curvature friction pendulum system (VCFPS) is proposed in this study. The radius of the curvature of VCFPS is lengthened with an increasing of the isolator displacement. Therefore, the fundamental period of the base-isolated structure can be shifted further away from the predominant period of near-fault ground motions. Finite element formulations for VCFPS have also been proposed in this study. The numerical results show that the base shear force and story drift of the superstructure during near-fault ground motion can be controlled within a desirable range with the installation of VCFPS. Therefore, the VCFPS can be adopted for upgrading the seismic resistance of the structures adjacent to an active fault.

Analytical and Experimental Seismic Studies of Transformers Isolated with Friction Pendulum System and Design Aspects

2001 ◽  
Vol 17 (4) ◽  
pp. 569-595 ◽  
Author(s):  
Selahattin Ersoy ◽  
M. Ala Saadeghvaziri ◽  
Gee-Yu Liu ◽  
S. T. Mau
Keyword(s):  
Parametric Study ◽  
Experimental Studies ◽  
Advanced Technology ◽  
Combination Rules ◽  
Ground Acceleration ◽  
Maximum Displacement ◽  
Isolation System ◽  
Pendulum System ◽  
Friction Pendulum ◽  
Friction Pendulum System

This paper presents the results of analytical and experimental studies on the use of an advanced technology for seismic rehabilitation and design of substation transformers. The isolation system, known as Friction Pendulum System (FPS), combines the concepts of sliding bearings and pendulum motion. Discussion of formulation is followed by an extensive parametric study using a typical transformer. Among parameters are peak ground acceleration, bidirectional motions, effect of vertical motion, and isolation radius. Inertia reduction and the maximum displacement of the system are the criteria used in evaluating the seismic response and the effectiveness of FPS bearings. Using the results of the parametric study, charts that can be used in design are developed for each criterion. Furthermore, two commonly used response combination rules, namely SRSS and CQC, are evaluated, and recommendations are made with regard to the suitability of each method in estimating the total responses under orthogonal motions. Finally, the results of an experimental study, which considers 1-D, 2-D, and 3-D responses of fixed and base isolated transformer models supporting a bushing, are presented. Experimental results are consistent with the analytical results and further support the effectiveness of FPS bearings in reducing inertia forces, thus, providing a suitable procedure to mitigate the seismic hazard of substation transformers.

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