scholarly journals Numerical Analysis on the Ground Vibration Isolation of Duxseal

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
M. Gao ◽  
S. P. Tian ◽  
R. He ◽  
Y. Wang ◽  
Q. S. Chen
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Free Field ◽  
Three Dimensional ◽  
Ground Vibration ◽  
Vibration Source ◽  
Isolation System ◽  
Vertical Excitation ◽  
Thin Layer Method ◽  
Active Vibration

A new kind of vibration screening material, Duxseal, with a high damping ratio is proposed to be used as an active vibration barrier in the free field. To investigate the influence of width, thickness, and embedded depth of using Duxseal on vibration reduction, numerical studies are performed using a three-dimensional (3D) semianalytical boundary element method (BEM) combined with a thin-layer method (TLM). The isolation effectiveness of Duxseal in ground vibration is also compared with the traditional wave impeding block (WIB). The numerical results show that Duxseal performed exceedingly well in screening ground vibrations in the free field. The effectiveness of the vibration isolation increases with the increase in the width, thickness, and embedded depth of the Duxseal material, within a certain range, under harmonic vertical excitation. In addition, Duxseal is much more effective for isolating ground vibration than the traditional WIB. The performance of Duxseal in isolating ground vibration is relatively stable along the distance away from the vibration source, while the amplitude attenuation ratio bounces upward when the distance away from the vibration source increases for the WIB isolation system.

A Study of Active Vibration Isolation

1985 ◽  
Vol 107 (4) ◽  
pp. 392-397 ◽  
Author(s):  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Vibration Isolation ◽  
Control Method ◽  
Feedforward Control ◽  
Ground Vibration ◽  
Design Parameters ◽  
Isolation Method ◽  
Isolation System ◽  
Active Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

For the purpose of suppressing ground vibration produced by vibrating machines, such as forging hammers, press machines, etc., this paper presents an active vibration isolation method. Unlike conventional isolators, the active isolator proposed in this paper permits rigid support of the machines. First, the principle of the active isolation method is shown, and the system equations are derived. Secondly, the characteristics and the design parameters of the active isolation system are presented. Thirdly, from the point of view of the feedforward control method, the dynamic compensators are designed so as to sufficiently suppress the exciting force. Finally, an experiment is carried out to demonstrate that the active isolator is applicable for suppressing the ground vibration.

Optimal Design of Active Vibration Isolation System

1988 ◽  
Vol 110 (1) ◽  
pp. 42-48 ◽  
Author(s):  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Optimal Design ◽  
Vibration Isolation ◽  
Optimization Technique ◽  
Design Procedure ◽  
Ground Vibration ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
Series Type ◽  
Active Vibration Isolation

In order to eliminate ground vibration produced by machines such as forge hammers, press machines, etc., this paper presents a systematic and optimal design procedure of an active vibration isolation system which permits rigid support of machines. First, the principle of the active vibration method is presented. Secondly, from the viewpoint of feedback control, the active vibration isolation system with a series-type dynamic compensator is constructed. Thirdly, with the air of a parameter optimization technique, the necessary conditions for optimality of the system are derived. Fourthly, for the purpose of solving the conditions, an iterative algorithm based upon a quasi-Newton method is proposed. Finally, by using the design procedure, the active vibration isolation system is designed, and the effectiveness to isolate the vibration is discussed.

Adaptive Least-Mean Square Feed-Forward Control With Actuator Saturation by Direct Minimization

2005 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh
Keyword(s):  
Vibration Isolation ◽  
Actuator Saturation ◽  
Ground Vibration ◽  
Lms Algorithm ◽  
Mean Square ◽  
Least Mean Square ◽  
Control Effort ◽  
Isolation System ◽  
Active Vibration ◽  
The Cost

The least-mean squares (LMS) adaptive feedforward algorithm is used widely for vibration and noise cancellation. If reference signals become large enough to saturate that actuators, the filter coefficients in such algorithms can diverge. The leaky LMS method limits the controller effort by augmenting the objective function by a weighted control effort, and is known to attain good performance and avoid growth of filter coefficients for well-chosen weights. We propose an algorithm that seeks to directly minimize the mean-square cost in the presence of saturation. We derive the true stochastic gradient of the cost for systems with saturation with respect to the filter coefficients and obtain an adaptation rule very close to that of the filtered-x algorithm, but in the proposed algorithm, the reference filter is a time-varying modification of the secondary channel. In simulations of an active vibration isolation system with actuator limits subject to random ground vibration, the leaky LMS algorithm attains its best performance with actuation weights small enough to allow significant actuator saturation but large enough to prevent divergence. The proposed algorithm attains performance better that attained by the leaky LMS algorithm, and does not require the selection of weights.

Research on Adaptive Feedforward Control Algorithm of Electromagnetic Active Vibration Isolation System

2012 ◽  
Vol 150 ◽  
pp. 80-84
Author(s):  
Jin Guang Zhang ◽  
Nan Xiang ◽  
Zuo Chao Xiao ◽  
Guo Ping Ding
Keyword(s):  
Vibration Isolation ◽  
Feedforward Control ◽  
Lms Algorithm ◽  
Vibration Source ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
Simulation Results ◽  
Adaptive Feedforward ◽  
Active Vibration Isolation

Feedforward control method to control vibration in the active vibration isolation system was discussed. By introducing the FIR filter as the feedforward link, using the mean-square deviation of system error as the performance index and utilizing the LMS algorithm to obtain the optimal parameters of controller, the design of adaptive feedforward controller was fulfilled. The simulation results showed that: for the active vibration isolation system with regularly vibration source, adopting adaptive filter method of feedforward control has notable effect. The contrast experiment with using the PID controller further verified the simulation results.

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.

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