scholarly journals The Roball

2002 ◽  
Vol 35 (3) ◽  
pp. 204-207 ◽  
Author(s):  
William H. Robinson
Keyword(s):  
Seismic Isolation ◽  
Inverted Pendulum ◽  
Experimental Results ◽  
Flat Plates ◽  
Isolation System ◽  
Friction Forces ◽  
New Device ◽  
System A ◽  
Full Scale Tests ◽  
User Friendly

Robinson Seismic's latest developments in seismic isolation includes a new device, the RoballTM, for seismically isolating structures during earthquakes. This advance is a new concept for seismic isolation based on the principle of the inverted pendulum. It consists of 'friction balls' or 'Roballs' moving between upper and lower spherical like cavities or flat plates. The Roballs are filled with a material which is able to provide the friction forces required to absorb the energy from numerous earthquakes while supporting the structure. The Roball technique is expected to enable light and in the future possibly heavy structures to be more economically seismically isolated. As part of a program to develop a user friendly 'seismic isolation system' a series of full-scale tests have been carried out on a number of possible designs including three approaches for vertical pressures of -1 MPa resulting in coefficients of friction of -0.1 to -0.4. In this paper we present the preliminary experimental results.

Application of Seismic Isolation Systems to High-Raised Houses in Lowland Regions

2014 ◽  
Author(s):  
H.-C. Su ◽  
C. S. Tsai
Keyword(s):  
Seismic Isolation ◽  
Water Levels ◽  
Experimental Results ◽  
Isolation System ◽  
Flood Resistance ◽  
Property Loss ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Rich Countries ◽  
Flood Prone Areas

According to the statistics of the World Bank between years 1970–2010, most economy losses caused by disasters in rich countries were due to floods and earthquakes. The East Asia was the most disastrous area in terms of the death toll caused by earthquakes, which proved that the earthquake is unpredictable. To cope with the crisis of the rise of the sea level, the concept of Marine Cities has been proposed. The most famous one among these concepts is the Dutch amphibious house. People living in earthquake and flood prone areas should be aware of the threat from oceans. Therefore, Ministry of Interior in Taiwan passed the rule 4 No. 2 in the chapter of the design and construction regulations to allow the use of high-raised buildings for reducing life and property loss. Furthermore, the most threatening natural hazards we are facing over a long period of time are floods and earthquakes. When are focusing on the flood resistant buildings in flood-prone areas, we should also aim at the prevention of earthquake disasters. The purpose of this study is to simulate the seismic behavior of the high-raised structures with different water levels, which are capable of flood resistance. We also propose a new seismic isolation system for these structures and study its efficiency in protecting these types of structures from earthquake damage. It appears from experimental results that the seismic responses of high-raised houses have been significantly reduced by the proposed device. Experimental results also disclosed that the proposed concept in this study is feasible for protecting structures in lowlands from damage resulting from floods as well as earthquakes.

Research about Rolling Friction Pendulum Seismic Isolation System on Ellipse Track

2012 ◽  
Vol 594-597 ◽  
pp. 1749-1752
Author(s):  
Jiang Pan ◽  
Nan Ge ◽  
Li Ting Yao
Keyword(s):  
Seismic Isolation ◽  
Lagrange Equation ◽  
Rolling Friction ◽  
Bottom Plate ◽  
Isolation System ◽  
Friction Forces ◽  
Pendulum System ◽  
Vibration Period ◽  
Building Model ◽  
Friction Pendulum

A theoretical analyzing approach about a class of seismic isolation system RFPS (Rolling Friction Pendulum System) is presented.. It starts from the Lagrange equation in multiply body dynamics. This system consists of a roller which is placed in the vicinity of two ellipse concave slides. Computation results for ellipse slide show that it has the three kinds of necessary functions required for an effective isolation system. The relatively long vibration period provides the necessary isolation capability, the gravity provides the reposition capability, and the friction couple, formed with the rolling friction forces at the contacting surface on the top and bottom plate respectively, provides the energy dissipation capability. The evaluation results for a practical building model shows that RFPS has a satisfactory seismic isolation effect.

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.

A novel geometry error measurement methodology for coaxiality evaluation

2020 ◽  
pp. 095440542096817
Author(s):  
Zhang Yingjie ◽  
Ge Liling
Keyword(s):  
Weighted Least Squares ◽  
Measurement Data ◽  
Coordinate Frame ◽  
Laser Sensor ◽  
New Device ◽  
System A ◽  
Measurement Methodology ◽  
Measurement Principle ◽  
3D Profile ◽  
Geometry Error

In this paper, we proposed a new device for geometry errors measurement and coaxiality evaluation, and the corresponding methodology for coaxiality evaluation from measurement data is presented, which allows to characterize multiple holes at a time. Unlike traditional measurement system a laser sensor is mounted onto out of the holes so that multi-hole surfaces can be “seen” by the senor when it rotates around a fixed axis. First the intersections (or ellipse profiles) of the sensor’s scanning plane and holes, are computed by fitting. Then, the center coordinates and profile points of the ellipse are computed and transformed to the 3D global coordinate frame. Finally the centerline of the hole is determined from the 3D profile points by using a weighted least-squares fitting algorithm. In addition, to reduce the effect of noises on the measurement result, error analysis and compensation techniques are studied to improve the measurement accuracy. A case study is presented to validate the measurement principle and data processing approach.

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.

Sliding Mode Control for Wheeled Inverted Pendulum

2014 ◽  
Vol 971-973 ◽  
pp. 714-717 ◽  
Author(s):  
Xiang Shi ◽  
Zhe Xu ◽  
Qing Yi He ◽  
Ka Tian
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
High Performance ◽  
Inverted Pendulum ◽  
Sliding Mode ◽  
Experimental Results ◽  
Control Law ◽  
Collaborative Simulation ◽  
Mode Control ◽  
Wheeled Inverted Pendulum

To control wheeled inverted pendulum is a good way to test all kinds of theories of control. The control law is designed, and it based on the collaborative simulation of MATLAB and ADAMS is used to control wheeled inverted pendulum. Then, with own design of hardware and software of control system, sliding mode control is used to wheeled inverted pendulum, and the experimental results of it indicate short adjusting time, the small overshoot and high performance.

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.

Identification and Model Predictive Position Control of Two Wheeled Inverted Pendulum Mobile Robot

2015 ◽  
Vol 73 (6) ◽  
Author(s):  
Amir A. Bature ◽  
Salinda Buyamin ◽  
Mohamad N. Ahmad ◽  
Mustapha Muhammad ◽  
Auwalu A. Muhammad
Keyword(s):  
Mathematical Model ◽  
System Identification ◽  
Mobile Robot ◽  
Inverted Pendulum ◽  
Position Control ◽  
Superior Performance ◽  
System A ◽  
Wheeled Inverted Pendulum ◽  
Simulation Results ◽  
Real Plant

In order to predict and analyse the behaviour of a real system, a simulated model is needed. The more accurate the model the better the response is when dealing with the real plant. This paper presents a model predictive position control of a Two Wheeled Inverted Pendulum robot. The model was developed by system identification using a grey box technique. Simulation results show superior performance of the gains computed using the grey box model as compared to common linearized mathematical model. 

Pl@ntwood: A Computer-Assisted Identification Tool for 110 species of amazon trees based on wood Anatomical Features

IAWA Journal ◽  
2011 ◽  
Vol 32 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Carolina Sarmiento ◽  
Pierre Détienne ◽  
Christine Heinz ◽  
Jean-François Molino ◽  
Pierre Grard ◽  
...  
Keyword(s):  
Tree Species ◽  
Tropical Species ◽  
Computer Assisted ◽  
Accurate Identification ◽  
Anatomical Features ◽  
System A ◽  
Microscopic Features ◽  
On Line ◽  
User Friendly ◽  
Identification Tool

Sustainable management and conservation of tropical trees and forests require accurate identification of tree species. Reliable, user-friendly identification tools based on macroscopic morphological features have already been developed for various tree floras. Wood anatomical features provide also a considerable amount of information that can be used for timber traceability, certification and trade control. Yet, this information is still poorly used, and only a handful of experts are able to use it for plant species identification. Here, we present an interactive, user-friendly tool based on vector graphics, illustrating 99 states of 27 wood characters from 110 Amazonian tree species belonging to 34 families. Pl@ntWood is a graphical identification tool based on the IDAO system, a multimedia approach to plant identification. Wood anatomical characters were selected from the IAWA list of microscopic features for hardwood identification, which will enable us to easily extend this work to a larger number of species. A stand-alone application has been developed and an on-line version will be delivered in the near future. Besides allowing non-specialists to identify plants in a user-friendly interface, this system can be used with different purposes such as teaching, conservation, management, and selftraining in the wood anatomy of tropical species.

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.

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