scholarly journals Seismic Resistance and Parametric Study of Building under Control of Impulsive Semi-Active Mass Damper

2021 ◽  
Vol 11 (6) ◽  
pp. 2468
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Frequency Ratio ◽  
Efficiency Index ◽  
Reduction Ratio ◽  
Seismic Resistance ◽  
Control Effect ◽  
Active Mass ◽  
High Rise ◽  
Mass Damper ◽  
Active Mass Damper ◽  
External Forces

When high-rise buildings are shaken due to external forces, the facilities of the building can be damaged. A Tuned Mass Damper (TMD) can resolve this issue, but the seismic resistance of TMD is exhausted due to the detuning effect. The Impulsive Semi-Active Mass Damper (ISAMD) is proposed with fast coupling and decoupling at the active joint between the mass and structure to overcome the detuning effect. The seismic proof effects of a high-rise building with TMD and ISAMD were compared. The numerical analysis results indicate that: (1) the reduction ratio of the maximum roof displacement response and the mean square root of the displacement reduction ratio of the building with the ISAMD were higher than 30% and 60%, respectively; (2) the sensitivity of the efficiency index to the frequency ratio of the ISAMD was very low, and detuning did not occur in the building with the ISAMD; (3) to achieve stable seismic resistance of the ISAMD, its frequency ratio should be between 2 and 4; (4) the amount of displacement of the control mass block of the ISAMD can be reduced by enhancing the stiffness of the auxiliary spring of the ISAMD; and (5) the proposed ISAMD has a stable control effect, regardless of the earthquake distance.

Fundamental Study of Active Mass Damper for Improving Livability of Houses Against Traffic Vibration

2004 ◽  
Author(s):  
Yukito Matsumoto ◽  
Osamu Hasegawa ◽  
Ikuo Shimoda ◽  
Kazuto Seto
Keyword(s):  
Complex Geometry ◽  
Control Effect ◽  
Fundamental Study ◽  
Active Mass ◽  
Response Characteristics ◽  
Population Concentration ◽  
Mass Damper ◽  
Active Mass Damper ◽  
Slender Structure ◽  
External Forces

In Japan, there are many houses built on limited space and also besides side of causeways and railroads, due to population concentration in the cities in recent years. Houses with 3-stories or slender structure houses are susceptible to traffic vibration induced by external forces. This affect frequency creates an uncomfortable environment for habitation. Because houses often have a complex geometry, it is difficult to establish the vibration characteristics of a structure. Furthermore, the response characteristics of a house will change with environmental condition. To address some of these issues, an Active Mass Damper (AMD) has developed in order to supply for users with a reasonable price. This AMD has a mass of 176kg in weight supported by guide springs, and driven by an AC servomotor and a wire rope. The AMD is controlled by two methods, LQ Control and Direct Displacement Feedback (DDFB) Control. In this report, a control effect is examined through simulation when the AMD is installed in the RF level of a 3-story house model. The simulation results are demonstrated that the AMD could improve the uncomfortable environment in houses. A matter of particular note was reduction of about 4 dB in the overall vibration level. Concerning an experimental study about this equipment, refer to the following report, “Fundamental experiment of Active Mass Damper for houses against traffic vibration”.

Fundamental Study of Active Mass Damper for Improving Livability of Houses Against Traffic Vibration: Substantiation Test

2004 ◽  
Author(s):  
Osamu Hasegawa ◽  
Jyunji Okabe ◽  
Toyohiko Higashida ◽  
Yukito Matsumoto
Keyword(s):  
Complex Geometry ◽  
Vibration Level ◽  
Fundamental Study ◽  
Active Mass ◽  
Target Weight ◽  
Response Characteristics ◽  
Close Proximity ◽  
Mass Damper ◽  
Active Mass Damper ◽  
External Forces

In Japan, there are many houses built in limited space as well as in close proximity to causeways and railroads, due mainly to concentration of population in the cities in recent years. Slender structures and especially 3-story houses are susceptible to vibration induced by external forces such as traffic. This effect often creates an uncomfortable environment for habitation. Because houses often have a complex geometry, it is difficult to establish the vibration characteristics of a structure. Furthermore, the response characteristics of a house will change with environmental conditions. A prototype Active Mass Damper (AMD) has been developed to address some of these issues. This has been tested in an exhibition house in Tokyo. It uses two AMD’s of 1,725N mass each for both X-axis and Y-axis. Both AMD’s are applied in X and Y directions and are installed at RooF level, they are controlled by Direct Displacement Feedback (DDFB). The test showed that the AMD could dramatically reduce vibration. Of particular note was reduction about 6dB to 8dB (L10) in the first mode of vibration even though the house mass is double the prototype target weight. Also, vibration was dramatically decreased by the AMD on 3rd floor of the house. Vibration level and comfort are important criteria for this kind of system.

scholarly journals Active Mass Damper for Reducing Wind and Earthquake Vibrations of a Long-Period Bridge

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 66
Author(s):  
Seongkyu Chang
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Harmonic Load ◽  
Control Effect ◽  
Linear Quadratic ◽  
Active Mass ◽  
Long Period ◽  
Bridge Model ◽  
Mass Damper ◽  
Active Mass Damper

An active mass damper (AMD) was developed that uses a linear motor and coil spring to reduce the vertical vibration of a long-period cable-stayed bridge subjected to wind and earthquake loads. A scaled-down bridge model and AMD were fabricated, and the control effect of the AMD was investigated experimentally and analytically. The AMD was controlled via a linear quadratic Gaussian algorithm, which combines a linear quadratic regulator and Kalman filter. The dynamic properties were investigated using a 1/10 scale indoor experimental model, and the results confirmed that the measured and analytical accelerations were consistent. A vibrator was used to simulate the wind-induced vibration, and the experimental and analytical results were consistent. The proposed AMD was confirmed to damp the free vibration and harmonic load and increase the damping ratio of the bridge model from 0.17% to 9.2%. Finally, the control performance of the proposed AMD was numerically investigated with the scaled-down bridge model subjected to the El Centro and Imperial Valley-02 earthquakes. These results were compared with those of a TMD, and they confirmed that the proposed AMD could reduce excessive vertical vibrations of long-period cable-stayed bridges subjected to wind and earthquakes.

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