scholarly journals Effect of Seismic Isolation with Triple Friction Pendulum Isolator Device on Weight Optimization of Steel Plane Frames

2021 ◽  
Vol 13 (3) ◽  
pp. 79-92
Author(s):  
Refik Burak TAYMUŞ ◽  
İbrahim AYDOĞDU
Keyword(s):  
Seismic Isolation ◽  
Weight Optimization ◽  
Plane Frames ◽  
Friction Pendulum

scholarly journals A comparative study of base isolation devices in light rail transit structure featured with lead rubber bearing and friction pendulum system

2018 ◽  
Vol 195 ◽  
pp. 02013
Author(s):  
Santi Nuraini ◽  
Asdam Tambusay ◽  
Priyo Suprobo
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Light Rail ◽  
Rail Transit ◽  
Light Rail Transit ◽  
Pendulum System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Friction Pendulum ◽  
Friction Pendulum System

Advanced nonlinear analysis in light rail transit (LRT) structures has been undertaken to examine the influence of seismic isolation devices for reducing seismic demand. The study employed the use of two types of commercially available bearings, namely lead rubber bearing (LRB) and friction pendulum system (FPS). Six LRT structures, designed to be built in Surabaya, were modelled using computer-aided software SAP2000, where each of the three structures consisted of three types of LRB and FPS placed onto the pier cap to support the horizontal upper-structural member. Nonlinear static pushover and dynamic time history analysis with seven improved ground motion data was performed to gain improved insights on the behavioural response of LRT structures, allowing one to fully understand the supremacy of seismic isolations for protecting the structure against seismic actions. It is shown that both devices manage to isolate seismic forces, resulting in alleviation of excessive base shear occurring at the column. In addition, it is noticeable that the overall responses of LRB and FPS shows marginal discrepancies, suggesting both devices are interchangeable to be used for LRT-like structures.

Weight Optimization of Steel Frames Using Genetic Algorithm

2002 ◽  
Vol 5 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Ribelito F. Torregosa ◽  
Worsak Kanok-Nukulchai
Keyword(s):  
Genetic Algorithm ◽  
Steel Frames ◽  
Optimization Procedure ◽  
Optimization Techniques ◽  
Weight Optimization ◽  
Discrete Variables ◽  
Design Problems ◽  
Plane Frames ◽  
Population Sizes ◽  
A New Technique

Genetic Algorithm (GA) is a new technique in optimization procedure that works best in design problems with discrete variables. It employs the survival of the fittest philosophy in determining the optimum combination. GA optimization procedure is applied to weight optimization of steel plane frames subjected to different load cases. Database of steel beam sizes is provided as the discrete variables. Both elitist and non-elitist search procedures are used to optimize the total weight of steel frames. Crossover types used are 20- and 50-percent uniform. Optimization result using population sizes 10, 20, and 40 are compared. Elitist search procedure showed superior results when compared to non-elitist for higher population sizes search because of its faster convergence rate. Performance of non-elitist is superior when using lesser population sizes. To examine the performance of genetic algorithms, case studies are conducted by varying material groups and the results are compared with the results from other optimization techniques. Genetic optimization showed superior results when compared to other techniques especially to problems with few material groupings.

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 Evaluating the Accuracy of an Equivalent Linear Model in Predicting Peak Displacement of Seismic Isolation Systems using Single Friction Pendulum Bearings

2021 ◽  
Author(s):  
Thanh-Truc Nguyen ◽  
Nhan Dinh Dao
Keyword(s):  
Linear Model ◽  
Seismic Isolation ◽  
Peak Displacement ◽  
Equivalent Linear ◽  
Linear And Nonlinear ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Friction Pendulum ◽  
Equivalent Linear Model ◽  
Motion Types

This study evaluates the accuracy of an equivalent linear model in predicting peak nonlinear time-history displacement of seismic isolation systems with single friction pendulum bearings. To perform this evaluation, dynamic response of numerical models of 120 isolation systems subjected to 390 strong earthquake ground motions, including motions with pulse and motions without pulse, was analyzed and statistically processed. The results show that the equivalent linear model can partly predict the peak displacement of its counterpart nonlinear model. However, the equivalent model can also underestimate or overestimate the peak displacement. On average sense, the equivalent linear model underestimates small peak displacement and overestimates large peak displacement. It is also observed that the relationship between linear and nonlinear peak displacements depends on ground motion types. Based on the analysis data, equations representing relationship between linear and nonlinear peak displacements at different reliable levels for different ground motion types were proposed. These equations can be used in practice.

Application of friction pendulum system to the main control room of a nuclear power plant

2009 ◽  
Vol 36 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Woo Bum Kim ◽  
Kangmin Lee ◽  
Gil Hee Kim
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
High Reliability ◽  
Time History ◽  
Control Room ◽  
Pendulum System ◽  
Friction Pendulum ◽  
Friction Pendulum System

An experimental and analytical study was performed to determine if the friction pendulum system (FPS) could be applied to the main control room (MCR) of a nuclear power plant as a seismic isolation device. A friction pendulum bearing was fabricated, and the dynamic performance of that bearing was evaluated. A partial model of the MCR with FPS was tested on a shaking table. The model consisted of a cabinet, an access floor, and four friction pendulum bearings. An artificial time history based on the MCR floor response spectrum was used as an earthquake input signal for the test. Analytical and experimental results were compared to verifiy their correlation and to enable the experimental study to cover a range of parametersnot previously studied in other similar experiments. Through these comparisons, it was affirmed that the proposed FPS seismic isolation system can be applied, with high reliability, to the MCR of a nuclear power plant.

Comparative Studies of Base Isolation Systems Featured with Lead Rubber Bearings and Friction Pendulum Bearings

2016 ◽  
Vol 846 ◽  
pp. 114-119
Author(s):  
Arati Pokhrel ◽  
Jian Chun Li ◽  
Yan Cheng Li ◽  
Nicos Maksis ◽  
Yang Yu
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Time History ◽  
Elastic Base ◽  
Base Shear ◽  
Isolation Technique ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Isolation Systems ◽  
Friction Pendulum

Due to the fact that safety is the major concern for civil structures in a seismic active zone, it has always been a challenge for structural engineers to protect structures from earthquake. During past several decades base isolation technique has become more and more popular in the field of seismic protection which can be adopted for new structures as well as the retrofit of existing structures. The objective of this study is to evaluate the behaviours of the building with different seismic isolation systems in terms of roof acceleration, elastic base shear and inter-storey drift under four benchmark earthquakes, namely, El Centro, Northridge, Hachinohe and Kobe earthquakes. Firstly, the design of base isolation systems, i.e. lead rubber bearing (LRB) and friction pendulum bearing (FPB) for five storey RC building was introduced in detail. The non-linear time history analysis was performed in order to determine the structural responses whereas Bouc-Wen Model of hysteresis was adopted for modelling the bilinear behaviour of the bearings. Both isolation systems increase the fundamental period of structures and reduces the spectral acceleration, and hence reduces the lateral force cause by earthquake in the structures, resulting in significant improvement in building performance; however the Lead Rubber Bearing provided the best reduction in elastic base shear and inter-storey drift (at first floor) for most of the benchmark earthquakes. For the adopted bearing characteristics, FPB provided the low isolator displacement.

scholarly journals Seismic running safety of trains and a new type of seismic-isolation railway structure

2021 ◽  
Author(s):  
Xiu Luo
Keyword(s):  
Safety Assessment ◽  
Seismic Isolation ◽  
Inertial Force ◽  
Longitudinal Direction ◽  
3D Numerical Simulation ◽  
Lateral Direction ◽  
Pendulum System ◽  
Running Safety ◽  
New Type ◽  
Friction Pendulum

Abstract Until now, seismic-isolation structures have not yet been applied in the railway field. The reason is that though a seismic-isolation structure can reduce the inertial force to the structure, the energy absorption causes big response displacement on the structure, which adversely effects the running safety of the trains supported by the structure. In this paper, a methodology for seismic running safety assessment is introduced, and a new type of seismic-isolation foundation is proposed, which can convert the seismic response displacement in the lateral direction of track to the longitudinal direction that has a less adverse effect on the running safety of the train. The isolation foundation is composed of FPS (Friction Pendulum System) slider, concave plate and guide ditch. Moreover, through model experiments and 3D numerical simulation, it is verified that the proposed foundation can keep both the effects of the seismic isolation and the running safety of the train during an earthquake.

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