Verification of the Relation Between the Directions of Control Force and Responses in Active Seismic Isolation Device

2018 ◽  
Author(s):  
Keigo Nakamura ◽  
Nanako Miura ◽  
Akira Sone
Keyword(s):  
Active Control ◽  
Seismic Isolation ◽  
Seismic Waves ◽  
Base Isolation ◽  
Active Vibration Control ◽  
Control Force ◽  
Control Power ◽  
Active Vibration ◽  
Self Powered ◽  
Isolation Device

In this research, the focus is on the energy problem in active vibration control of a seismic isolation device using self-powered active control that regenerates electric power from kinetic energy of vibration system and uses it as control power. In recent years, it is proposed to install semi-active control or active control in an isolated structure to deal with seismic waves of various periods. However, since energy is required for control, there is a problem that the desired response reduction performance cannot be achieved when energy supply is interrupted at the time of a power outage. In our previous device, power is always given to the motor to control, thus power consumption is high. Therefore, the purpose of this research is to propose input method of control force that can reduce control power while keeping base isolation performance by classifying the role of the control force for each control phase and considering various combinations of input control force.

The Design and Application of Piezoelectric Friction Damper with Self-Powered and Sensing Control System

2010 ◽  
Vol 163-167 ◽  
pp. 2477-2481
Author(s):  
Na Xin Dai ◽  
Ping Tan ◽  
Fu Lin Zhou
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Active Control ◽  
Mechanical Energy ◽  
Active Vibration Control ◽  
Friction Damper ◽  
Active Vibration ◽  
Self Powered ◽  
Control Equation ◽  
Converse Piezoelectric Effect

To make the active and semi-active vibration control system in civil engineering get rid of external power supply, a new piezoelectric friction damper with self-power and sensing is designed in this paper and a semi-active control system based on this damper is presented. This system includes three key parts: a piezoelectric friction damper, a power generator based on the piezoelectric stack electro-mechanical energy conversion and a control circuit. It makes full use of the direct and converse piezoelectric effect. At the same time, it also overcomes the deficiency that the frictional force as damping can not be accurately desired in semi-active vibration control system. On the basis of it, the control equation of PFD is formulated. Numerical simulations for seismic protection of story isolation equipped with this system excited by a historical earthquake are conducted by MATLAB. Skyhook control is used to command a piezoelectric friction damper in the semi-active control. It is noticed that only one accelerometer is needed to monitor the response to realize the skyhook control, which greatly simplifies the classical semi-active vibration control system.

Self-Powered Active Vibration Control Using Regenerated Vibration Energy

1999 ◽  
Vol 11 (4) ◽  
pp. 310-314 ◽  
Author(s):  
Kimihiko Nakano ◽  
◽  
Yoshihiro Suda ◽  
Shigeyuki Nakadai ◽  
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Passive Control ◽  
High Efficiency ◽  
Active Vibration Control ◽  
Vibration Energy ◽  
Control Input ◽  
External Energy ◽  
Active Vibration ◽  
Self Powered

Active vibration control using regenerated vibration energy, i.e., self-powered active vibration control is proposed in which energy absorbed by a damper is stored in a condenser. An actuator produces control input using this stored energy. This requires no external energy. Energy used by the actuator is restricted to be less than energy regenerated. It is important to reduce energy consumption in the actuator. The control we developed requires less external energy than typical active control. A linear DC motor operating as an energy regenerative damper with high efficiency is used in experiments realizing self-powered active control and showing better isolation than passive control.

Experiment Verification of Seismic Isolation Device Having Charging Function

2017 ◽  
Author(s):  
Takashi Yamaguchi ◽  
Hayato Nakakoji ◽  
Nanako Miura ◽  
Akira Sone
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Systems ◽  
Seismic Isolation ◽  
Active Vibration Control ◽  
Vibration Reduction ◽  
Large Earthquake ◽  
Energy Regeneration ◽  
Active Vibration ◽  
Isolation Device

In late years, many base isolated structures are planned as seismic design, because they suppress vibration response significantly against large earthquake. In addition, to achieve greater safety, semi-active or active vibration control system is installed in the structures as. Semi-active and active vibration control systems are more effective to large earthquake than passive one vibration control system in terms of vibration reduction. However semi-active and active vibration control systems cannot operate as required when external power supply is cut off. To solve the problem of energy consumption, we propose a self-powered active seismic isolation device which achieves active control system using regenerated vibration energy. This device doesn’t require external energy to produce control force. The purpose of this paper is to propose the seismic isolation device having charging function and verified its performance by experiment. In our previous research[1], we proposed the new model and optimized the control system and passive elements such as spring coefficients and damping coefficients using genetic algorithm. As a result, we proposed the model which is superior to the previous model in terms of vibration reduction and energy regeneration. In this study, we conducted an experiment and show its results. As a results, we confirmed the vibration reduction and energy regeneration of the seismic isolation device having charging function.

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

Laminated Type Isolation Device for Light Weight Structure Using Urethane Elastomer

2017 ◽  
Author(s):  
Kengo Goda ◽  
Osamu Furuya ◽  
Kohei Imamura ◽  
Kenta Ishihana
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Light Weight ◽  
Loading Test ◽  
Isolation System ◽  
Seismic Safety ◽  
Base Isolation System ◽  
Weight Structure ◽  
Isolation Device ◽  
Urethane Elastomer

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material. In general, the isolation structure is used in high damping rubber. However, we pay attention to base isolation using urethane elastomer. Urethane elastomer has excellent elasticity, mechanical strength, abrasion resistance, weather resistance, oil resistance, impact resistance the absorbent, anti-vibration and excellent low-temperature properties. Furthermore, it is possible to impart various characteristics by a combination of isocyanate and polyol and chain extender, requires no large-scale apparatus, it has the advantage molecular design is easy. In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step. In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. Furthermore, the design equation is created by loading test using urethane elastomer. The validity of the design equation has been confirmed. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.

Base-Isolated Multi-Storey Reinforced Concrete Frame Structure Modal Analysis

2012 ◽  
Vol 204-208 ◽  
pp. 869-871
Author(s):  
Cai Hua Wang ◽  
Hui Jian Li ◽  
Jian Feng Wu
Keyword(s):  
Reinforced Concrete ◽  
Modal Analysis ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Reinforced Concrete Frame Structure ◽  
Before And After ◽  
Isolation Device

The multi-storey reinforced concrete frame structure used lead rubber pad as the base isolation device. The paper had modal analysis of base-isolated multi-storey reinforced concrete frame structure using the ANSYS software. Comparing the frequency and vibration mode before and after isolation under El-Centro wave, It concluded the leader rubber pad have seismic isolation effect for multi-storey reinforced concrete frame structure .

Active Vibration Control of a Triple Flexible Structures Combined With Actuators

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Yoshihiro Toba ◽  
Fumio Doi
Keyword(s):  
Vibration Control ◽  
Large Scale ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Low Frequency ◽  
Tall Buildings ◽  
Control Force ◽  
Active Vibration ◽  
Strong Winds ◽  
Lq Control

Abstract In order to realize living comfort of tall buildings by reducing the vibration of higher floors by strong winds, this paper proposes a new method of vibration control for flexible structures with a large scale. The higher a tall building the lower its natural frequency. Since obtaining sufficient force to control the lower frequency vibrations of tall buildings is a difficult task, controlling the vibration of ultra-tall buildings using active dynamic absorbers is nearly impossible. This problem can be overcome by placing actuators between a pair of two or three ultra-tall buildings and using the vibrational force of each building to offset the vibrational movement of its paired mate. Therefore, it is able to obtain enough control force under the low frequency when the proposed method is used. In this paper, a reduced-order model expressed by 2DOF system under taking into consideration for preventing spillover instability is applied to control each flexible structure. The LQ control theory is applied to the design of such a control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.

Evaluation of the Isolation System Influence in the Seismic Loading Analysis Applied to a Near Term Deployment Reactor

2009 ◽  
Author(s):  
R. Lo Frano ◽  
G. Forasassi
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Seismic Waves ◽  
Base Isolation ◽  
Methodological Approach ◽  
Response Spectra ◽  
Three Dimensional Model ◽  
Isolation System ◽  
Isolation Technique ◽  
Near Term

Nuclear power plant (NPP) design is strictly dependent on the seismic hazards and safety aspects related to the external events of the site. Passive vibration isolators are the most simple and reliable means to protect sensitive equipment from environmental shocks and vibrations. This paper concerns the methodological approach to treat isolation applied to a near term deployment reactor and its internals structures in order to attain a suitable decrease of response spectra at each floor along the height of the structure. The aim of this evaluation is to determine the seismic resistance capability of as-built structures systems and components in the event of the considered Safe Shutdown earthquake (SSE). The use of anti-seismic techniques, such as seismic isolation (SI) and passive energy dissipation, seems able to ensure the full integrity and operability of important structures and systems even in very severe seismic conditions. Therefore the seismic dynamic loadings, propagated up to the main reactor system and components, may be reduced by using the developed base-isolation system (high flexibility for horizontal motions) that might combine suitable dampers with the isolating components to support reactor structures and building. To investigate and analyze the effects of the mentioned earthquake on the considered reactor internals, a deterministic methodological approach, based on the evaluation of the propagation of seismic waves along the structure, was used. To the purpose of this study a numerical assessment of dynamic structural response behaviour of the structures was accomplished by means of the finite element approach and setting up, as accurately as possible, a representative three-dimensional model of mentioned NPP structures. The obtained results in terms of response spectra (carried out from both cases of isolated and not isolated seismic analyses) were compared in order to highlight the isolation technique effectiveness.

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