Study on TMD for Long Period Structure Using Air Floating Technique: Investigation of Fundamental Performance

2018 ◽  
Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi ◽  
Osamu Takahashi ◽  
Kunio Sanpei ◽  
Shoichi Sakamoto ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Shaking Table Test ◽  
Structural Response ◽  
Shaking Table ◽  
Inertia Force ◽  
Loading Test ◽  
Natural Period ◽  
Long Period ◽  
Static Loading Test

Natural period of architectural structure have been longer to be high-rise in recent years. Tuned Mass Damper (TMD) is applied for the structural response reduction in such a long period structure. In general since there are a lot of design cases using a guide rail for linear motion guide of the mass in TMD, the friction coefficient in assembled TMD becomes almost from 3/1000 to 5/1000. The friction coefficient leads an important problem in view point of performance design for long period structures because of that the friction force becomes a large compared with starting inertia force. In this study, new type TMD with air pressure floating technique has been examined to reduce a friction force for starting inertia force, and to set 0.01 m/s2 in starting acceleration as a performance target. This paper shows the evaluation results for fundamental performance from static loading test and shaking table test.

scholarly journals Dynamic Behavior of Ground Improved Using a Crushed Stone Foundation Wall

2019 ◽  
Vol 11 (10) ◽  
pp. 2767
Author(s):  
Su-Won Son ◽  
Pouyan Bagheri ◽  
Jin-Man Kim
Keyword(s):  
Dynamic Behavior ◽  
Shaking Table Test ◽  
Soft Soil ◽  
Shaking Table ◽  
Crushed Stone ◽  
Natural Period ◽  
Long Period ◽  
Acceleration Amplification ◽  
Short Period ◽  
Foundation Wall

The improvement of soft clay and dredged soils to carry structures is increasingly important. In this study, the dynamic behavior of a crushed stone foundation wall in clay soil was analyzed using a 1g shaking table test. The response accelerations and spectra for three input ground motions were analyzed relative to the distance from the foundation wall, confirming that the acceleration was damped from the outside. The acceleration according to the distance from the wall was not significant under long-period motions, while different responses were obtained under short-period motions. The increased ground stiffness provided by the crushed stone wall lowered the natural period of the ground, and the acceleration amplification under short-period seismic waves was larger than that under long-period waves. Finally, equations were derived to describe the relationship between the acceleration amplification ratio and distance from the wall. The slopes of the proposed equations are larger under shorter periods, implying that the change in acceleration change with distance from the wall is more significant under shorter periods. The results of this study can be used to inform the design of soft soil improvements and the structures built atop them.

Shaking Table Test Study on Mid-Story Isolation Structures

2012 ◽  
Vol 446-449 ◽  
pp. 378-381
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Yu Hong Ma ◽  
Chao Yong Shen
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Lead Rubber Bearing ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with lead rubber bearing are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

Seismic Mitigation Assessment of Building Using Multiple Direction Optimized-Friction Pendulum System

2008 ◽  
Author(s):  
C. S. Tsai ◽  
Wen-Shin Chen ◽  
Yung-Chang Lin ◽  
Chi-Lu Lin
Keyword(s):  
Finite Element ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Natural Period ◽  
Pendulum System ◽  
Friction Pendulum ◽  
Seismic Mitigation ◽  
Friction Pendulum System

In order to prevent a building near a fault from earthquake damage, in this study an advanced base isolation system called the multiple direction optimized-friction pendulum system (Multiple DO-FPS or MDO-FPS) is proposed and examined to address its mechanical behavior through the finite element formulation and evaluate its efficiency in seismic mitigation through a series of shaking table tests. On the basis of the finite element formulation, it is revealed that the natural period, the capacity of the bearing displacement and damping effect for the Multiple Direction Optimized-Friction Pendulum System (Multiple DO-FPS) change continually during earthquakes. Therefore, the MDO-FPS isolator can avoid possibility of resonance of enriched frequencies from ground motions and provide an efficient capacity of the bearing displacement and damping during the earthquakes. Simultaneously, the shaking table test results also illustrate that the Multiple DO-FPS isolator possesses an outstanding seismic mitigation capabilities.

Design and Manufacturing of a Multi-Stable Selectively Stiff Morphing Section Demonstrator

2019 ◽  
Author(s):  
D. Matthew Boston ◽  
Jose R. Rivas-Padilla ◽  
Andres F. Arrieta
Keyword(s):  
Structural Response ◽  
Experimental Results ◽  
Image Correlation ◽  
Stable States ◽  
Loading Test ◽  
Wing Section ◽  
Curved Structures ◽  
Trade Offs ◽  
Static Loading Test ◽  
And Performance

Abstract Morphing wings offer potential efficiency and performance benefits for aircraft fulfilling multiple mission requirements. However, the design of shape adaptable wings is limited by the inherent design trade-offs of weight, aerodynamic control authority, and load-carrying capacity. A potential solution to this trilemma is proposed by exploiting the stiffness adaptability of thin, curved structures which geometric instability results in two statically stable states. We design and manufacture a morphing wing section demonstrator composed of two compliant 3D printed ribs monolithically embedded with the proposed bi-stable elements. The demonstrator’s structural response is numerically modelled and compared with experimental results from a static loading test. A deflection field of the response under mechanical actuation is obtained through digital image correlation. Numerical and experimental results indicate the capability of the wing section to achieve four distinct stable configurations with varying global stiffness behavior.

Study on the Suitability of Seismic Isolation Technologies for Rural Buildings

2013 ◽  
Vol 353-356 ◽  
pp. 2221-2227
Author(s):  
Guang Hui Zhang
Keyword(s):  
Friction Coefficient ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Economic Conditions ◽  
Difficulty Level ◽  
Earthquake Disaster ◽  
Sliding Isolation ◽  
Rural Buildings ◽  
Collapse Ratio

Rural buildings are subject to the most serious damage and the highest collapse ratio in earthquake disaster. It is urgent at present to develop seismic isolation technologies applicable to rural buildings under current rural economic conditions of China. Through comparing the existing domestic seismic isolation technologies in respects of the acquisition difficulty level, price and friction coefficient of material and the placement of sliding material, and analyzing the result of simulated shaking table test respectively with the gravel foundation isolation technology and the gravel sliding isolation technology, this paper points out matters needing attention during the development of seismic isolation technologies for rural buildings.

Shaking Table Test of Quarter Scale 20 Story RC Moment Frame Building Subjected to Long Period Ground Motions

2016 ◽  
Vol 11 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Kuniyoshi Sugimoto ◽  
◽  
Kenji Yonezawa ◽  
Hideo Katsumata ◽  
Hiroshi Fukuyama ◽  
...  
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Test Results ◽  
Nonlinear Fem ◽  
Moment Frame ◽  
Building Model ◽  
Long Period ◽  
Frame Building ◽  
Long Duration ◽  
Current Design

Shaking table test of a quarter-scale 20-story reinforced concrete building model was carried out. Employed input waves were kinds of long period and long duration ground motion. Test results showed that structural slabs were fully effective for building strength, which could be expressed in detailed analysis using nonlinear FEM. However, the observed hysteretic damping after yielding was fairly smaller than the expected by the current design custom, which caused smaller and unsafe estimated response than that observed in the test.

BEHAVIOR OF NONSTRUCTURAL COMPONENT SUPPORTED BY HANGER BOLTS UNDER SEISMIC EXCITATIONS BY SHAKING TABLE TEST

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Haeyoung Kim ◽  
Kunio Mizutani ◽  
Syojiro Motoyui
Keyword(s):  
Shaking Table Test ◽  
Great East Japan Earthquake ◽  
Shaking Table ◽  
Structural Members ◽  
Shaking Table Tests ◽  
Seismic Excitations ◽  
Nonstructural Components ◽  
Pipe System ◽  
Long Period ◽  
Steel Building

During the Great East Japan Earthquake of March 2011, nonstructural components, such as pipe systems, ducts, cable racks and ceilings were severely damaged while main structural members in the building were not damaged seriously. Pipes, cable racks, apparatus and ducts’ hanger bolts were ruptured causing the equipment to fall down. Because of these damages, buildings cannot be used for a long period of time and one person was killed by pipe’s falling in Japan. In this study, the behaviors of nonstructural components are investigated by conducting shaking table tests to verify the cause of damage. More specifically, damage to hanger bolts is investigated by simulating its rupturing mechanism through shaking table test. To simulate the real installation condition of nonstructural components, apparatus-duct-pipe system supported by hanger bolts is selected as specimen. Roof floor response wave at the actual 5-story steel building under the Great East Japan Earthquake and sweep wave are used for the input waves. The maximum response acceleration was about 4 G in X direction under response wave 75% and the damage occurred at the metal fitting which is the connection part between braces and hanger bolt. And without installing braces, the upper hanger bolts at the fixed supporting part were ruptured easily since the natural frequency of the specimen closed to those of target building during excitations and the response became huge.

Research and Development of Intelligent Seismic Isolation System Using Air Bearing

2008 ◽  
Author(s):  
Satoshi Fujita ◽  
Keisuke Minagawa ◽  
Mitsuru Miyazaki ◽  
Go Tanaka ◽  
Osamu Takahashi
Keyword(s):  
Friction Coefficient ◽  
Seismic Wave ◽  
Seismic Isolation ◽  
Seismic Waves ◽  
Air Bearing ◽  
Natural Period ◽  
Isolation System ◽  
Long Period ◽  
Isolation Device ◽  
Isolation Performance

This study aims at research and development of the intelligent seismic isolation system using air bearings as isolation device and Earthquake Early Warning (EEW) as trigger of isolation system. In October 2007, EEW was started providing to resident of Japan. The EEW system expects earthquake intensity and arrival time at particular place by analysis of seismic wave that was observed near the earthquake center. Therefore social and technical application of the system is strongly expected for suppression of disaster scale. On the other hand, 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. In metropolises of Japan such as Tokyo, Osaka and Nagoya, it is expected that long period seismic waves are excited in large earthquakes because these are located on sedimentary layers. Therefore the isolation system having very long natural period or no natural period is required. In this study, we propose an isolation system having no natural period by using air bearing as isolation device. Air bearing is a bearing that can reduce contact friction between floor and the bearing by thin air film produced by compressed air. In general, the air bearing is used as heavy machinery moving equipment. The approximate friction coefficient is 0.0005 to 0.001, so that the system using air bearing almost isolates seismic wave. In addition, the EEW is applied as trigger of isolation. The EEW is applied for turning gas and electrical heater off, too. P-wave sensor is also equipped and it can operate as trigger in case of near-field earthquake or when EEW system could not work properly. Furthermore, steel plate equipped at the bottom of the air bearing can operate as friction bearing when air bearing does not work. In this paper, we describe results of earthquake response analysis of the intelligent isolation system using air bearing. From results of the analysis, it was confirmed that response acceleration depends on friction coefficient only, and the system has good isolation performance not only against typical seismic wave, such as El Centro wave, but also against long period seismic wave. However residual displacement remains after seismic input stopped. Additionally, experimental test was executed so as to investigate basic performance of isolation. As a result, it was confirmed that the isolation system has good isolation performance.

Discussion on Masonry Structure Model Mechanical Property Test

2012 ◽  
Vol 238 ◽  
pp. 659-662 ◽  
Author(s):  
Gong Lian Chen ◽  
Lin Jun Si
Keyword(s):  
Shaking Table Test ◽  
Mechanical Test ◽  
Dynamic Test ◽  
Masonry Structure ◽  
Shaking Table ◽  
Structure Model ◽  
Loading Test ◽  
Mixture Ratio ◽  
Static Test ◽  
Masonry Material

The problems in the mechanical test of masonry structure model were discussed in this paper, including the masonry material, similar relationship, shaking table test device, judgment of wall cracking and number of cycles in pseudo-static loading test. The conclusions are: (1) for the masonry material mechanical test, usually the size decreased the strength increased, but if the laying method and appropriate adjustments in the process of the test mixture ratio, the size effect can be greatly reduced; (2) In the dynamic test of the masonry structure, for the gravity distortion model, the common way is the external prestressing method, but in this method the tension force is not constant, which is differ from the actual situation; (3) The wall cracking can be judged when the main tension crack of the wall appeared; (4) The loading cycle in the pseudo-static test of masonry wall would be twice.

scholarly journals Collapse Analysis of a Two-Span Reinforced Concrete Bridge Model

2021 ◽  
Vol 11 (19) ◽  
pp. 8935
Author(s):  
Yale Li ◽  
Zhouhong Zong ◽  
Bingwen Yang ◽  
Zhanghua Xia ◽  
Yuanzheng Lin ◽  
...  
Keyword(s):  
Ground Motion ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Structural Response ◽  
Shaking Table ◽  
Collapse Mechanism ◽  
Girder Bridges ◽  
Bridge Model ◽  
Collapse Resistance ◽  
Collapse Mode

The continuous girder bridge is the main type of small- and medium-sized bridges; however, it has poor collapse resistance and suffers frequent earthquake damage. In order to grasp its collapse mechanism and clarify the internal and external factors affecting its collapse resistance, a 1:3-scaled, two-span bridge model subjected to shaking table test research was taken as the research object. The factors such as seismic characteristics, multi-directional seismic coupling, span, pier height, and structural system type were analyzed to determine the influences on the collapse mode of the bridge. The numerical results showed that different ground motion characteristics led to different collapse modes. Vertical ground motion had little effect on the structural response of the bridge. The change of span and pier height significantly changed the collapse resistance. A seismic isolation design could improve the anti-collapse performance, but the collapse mode varied with the system. The final anti-collapse design suggestions could provide reference for the seismic reinforcement of existing continuous girder bridges and the seismic design of continuous girder bridges that will be constructed.

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