Investigation on Power Transmission for the Isolation System Mounting on Plate-Shell Coupled Structure

2014 ◽  
Vol 716-717 ◽  
pp. 631-634
Author(s):  
Lu Dai ◽  
Tie Jun Yang ◽  
Xu Hu ◽  
Han Bing Ke

An approach of combining the rigid body theory and improved Fourier series method is proposed to model the single-stage isolation system based on an elastic plate-shell coupled structure, and the isolation performance is investigated. Considering the practical problems of the machinery system design in the field of marine engineering, the influences of various structural parameters on the isolation performance for the isolation system is implemented. The numerical simulation results are given and discussed.

2018 ◽  
Vol 10 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Yong Wang ◽  
Ruo-Chen Wang ◽  
Hao-Dong Meng

Inerter, which is defined as a two-terminal mechanical element, has the characteristic that the force generated at its two terminals is proportional to the relative acceleration between its two ends. Here, the inerter is used in the vibration isolation system; eight kinds of one-stage inerter-based vibration isolators are presented in this paper. Dynamic equations of eight kinds of one-stage inerter-based vibration isolators are established, the natural frequency is considered, and the dynamic response and transmissibility are obtained using the time domain analysis method or the Laplace-transformed method. Four performance indexes are defined to evaluate their isolation performance and compared with the linear vibration isolator (LVI). The best structural parameters of these one-stage inerter-based vibration isolators are determined using the H[Formula: see text] optimization method based on the fixed-point theory, which aims to minimize the maximum transmissibility. The results show that compared with the LVI, some kinds of one-stage inerter-based vibration isolators can offer a better isolation performance according to the four performance indexes. Furthermore, the best vibration isolator among these vibration isolators is determined by the four performance indexes.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.


Author(s):  
Satoshi Fujita ◽  
Keisuke Minagawa ◽  
Mitsuru Miyazaki ◽  
Go Tanaka ◽  
Toshio Omi ◽  
...  

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.


2011 ◽  
Vol 211-212 ◽  
pp. 384-388
Author(s):  
Gui Mei Guo ◽  
Lin Hong

Sight-stabilizing mechanisms controlled by diaphragm springs and other damping elements is an important subordinate system of airborne sight stabilizing System. The performances of sight-stabilizing system depend on the characteristics of kinematics and dynamics of the system in a great extent. Among various external moments acting on the rod of the manipulator, such as those moments caused by damper, positioning spring, and restoration spring, the forces by diaphragm springs are most obvious. According to the structure form and motion peculiarity, the rod can be equivalent to a rigid body turning around a fix point. Simulation results reveal that the moment of the restoration spring to the rod is proportional to the angular displacement, and that the moment is the most prominent factor influencing the operating performances among all these moments. Through reasonable adjustments of structural parameters of the restoration spring, the performances of the sight-stabilizing system can be improved greatly; the analysis method provides a basis for guiding the design of concerned structural parameters of sight-stabilizing system.


2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Baoquan Kou ◽  
Yiheng Zhou ◽  
Xiaobao Yang ◽  
Feng Xing ◽  
He Zhang

In this paper, we describe a flat-type vertical-gap passive magnetic levitation vibration isolator (FVPMLVI) for active vibration isolation system (AVIS). A dual-stator scheme and a special stator magnet array are adopted in the proposed FVPMLVI, which has the effect of decreasing its natural frequency, and this enhances the vibration isolation capability of the FVPMLVI. The structure, operating principle, analytical model, and electromagnetic and mechanical characteristics of the FVPMLVI are investigated. The relationship between the force characteristics (levitation force, horizontal force, force ripple, and force density) and major structural parameters (width and thickness of stator and mover magnets) is analyzed by finite element method. The experiment result is in good agreement with the theoretical analysis.


2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881719 ◽  
Author(s):  
You Wang ◽  
Xinghua Zhu ◽  
Rong Zheng ◽  
Zhe Tang ◽  
Bingbing Chen

In this study, the applications of the cubic power law damping in vessel isolation systems are investigated. The isolation performance is assessed using the force transmissibility of the vessel isolation system, which is simplified as a multiple-degree-of-freedom system with two parallel freedoms. The force transmissibilities of different working conditions faced in practice are discussed by applying the cubic power law damping on different positions of the vessel isolation system. Numerical results indicate that by adding the cubic power law damping to an appropriate position, the isolation system can not only suppress the force transmissibility over the resonant frequency region but also keep the force transmissibility unaffected at the nonresonant frequency region. Moreover, the design of the nonlinear vessel isolation system is discussed by finding the optimal nonlinear damping of the isolation system.


2013 ◽  
Vol 819 ◽  
pp. 115-119 ◽  
Author(s):  
Hui Wang ◽  
Ze Yu Weng ◽  
Gan Xiang ◽  
Bo Lu ◽  
Hong Gang Ding ◽  
...  

The floating raft isolation system is widely used in the field of marine engineering for its vibration isolation effect. Along with the application of light thinning structure of the ship, the flexibility of foundation of floating raft isolation system makes the vibration isolation effect vary widely between the practical floating raft isolation system and its theoretical results. In order to research the vibration isolation effect of the floating raft isolation system on different flexibility of foundation, the floating raft isolation system with flexible foundation is designed in this paper, and the adjustable flexibility of foundation is achieved by using elastic beams. With simulation and analysis of test system in ADAMS, the results of the relationship between flexibility and vibration isolation effect are obtained.


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