Dynamical Analysis and Realization of an Adaptive Isolator

2017 ◽  
Vol 85 (1) ◽  
Author(s):  
Sun Xiuting ◽  
Shu Zhang ◽  
Jian Xu ◽  
Feng Wang
Keyword(s):  
Nonlinear Vibration ◽  
Structural Property ◽  
Vibration Isolation ◽  
Structural Parameters ◽  
Singularity Theory ◽  
Dynamical Analysis ◽  
Damping Properties ◽  
Isolation System ◽  
State Band ◽  
Stiffness And Damping

An adaptive vibration isolation system is proposed in this paper to combine the advantages of both linear and nonlinear isolators. Because of the proposed structural piecewise characteristics for different levels of response, the stiffness and damping properties could be designed according to the vibration performances. The adaptive stiffness and damping properties are achieved by the joined utilization of symmetrical precompression triangle-like structure (TLS) and column frame with cam. In order to design the control mechanism with optimum structural parameters, nonlinear vibration performances are analyzed by using averaging method and singularity theory. The parameter plane is divided into transition sets, and then the optimization criterions for structural design are provided according to multiple nonlinear vibration performances including frequency band for effective isolation, multisteady state band and resonance peak, etc. The experiment is carried out to verify the theoretical selection of desirable parameters and indicates the advantages and improvement of vibration isolation/suppression brought by the structural property adaptation. This study provides a novel method of achieving structural property adaptation for the improvement of isolation effectiveness, which shows the intelligent realization by passive components.

scholarly journals Modeling and Dynamics of a MDOF Isolation System

2017 ◽  
Author(s):  
Youshuo Song ◽  
Xiuting Sun
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
Structural Parameters ◽  
Structural Parameter ◽  
Isolation System ◽  
Passive Components ◽  
Vibration Isolation System ◽  
Joint Friction ◽  
Engineering Practices ◽  
Stiffness And Damping

This study analyzes the modeling and dynamics of a novel passive in Multi-Degree-of-Freedom (MDOF) vibration isolation platform which can achieve significant isolation effect. Symmetrical Scissor-Like structures (SLSs) are utilized in the proposed MDOF isolation platform as the supporting and isolation elastic components. Based on the mathematical modeling and theoretical analysis of the MDOF vibration isolation system with SLSs, the effect of structural parameter and joint friction on stiffness and damping properties is investigated. It is shown that due to geometric relations within the SLSs, the natural frequencies can be reduced via adjusting structural parameters of the SLS for different direction vibration isolation. Theoretical and experimental results show that the SLS isolation platform can achieve much better loading capacity and vibration isolation performance simultaneously by only using linear passive components because of the MDOF adjustable stiffness property. Therefore, with low costing and energy consumption, the proposed novel isolation platform can provide the improvement of vibration suppression in various engineering practices.

Research on Modeling and Optimization of a Dual Chamber Air Spring Vibration Isolation System

2013 ◽  
Vol 702 ◽  
pp. 310-317 ◽  
Author(s):  
Cheng Zhang ◽  
Jian Fu Zhang ◽  
Ping Fa Feng ◽  
Ding Wen Yu ◽  
Zhi Jun Wu
Keyword(s):  
Vibration Isolation ◽  
Structural Parameters ◽  
Dynamic Stiffness ◽  
Theoretical Models ◽  
Air Spring ◽  
Dual Chamber ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Spring System ◽  
Stiffness And Damping

To improve the vibration isolation performanceof an air spring system,the characteristics of the dynamic stiffness and damping of adual chamber air springwere first analyzed. A theoretical model ofa four dual chamber air springs system wasthen constructed,and through experimental verification,the theoretical and experimental curves showedthe same change trend.Based on the theoretical models, anobjective function used to optimize the structural parameters of an air springwas constructed. It was demonstrated that the vibration isolation performance of the air spring system was improved with the optimized parameters.

scholarly journals Electromagnetic and Mechanical Characteristics Analysis of a Flat-Type Vertical-Gap Passive Magnetic Levitation Vibration Isolator

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Baoquan Kou ◽  
Yiheng Zhou ◽  
Xiaobao Yang ◽  
Feng Xing ◽  
He Zhang
Keyword(s):  
Vibration Isolation ◽  
Mechanical Characteristics ◽  
Magnetic Levitation ◽  
Structural Parameters ◽  
Force Density ◽  
Vibration Isolator ◽  
Isolation System ◽  
Flat Type ◽  
Characteristics Analysis ◽  
Vertical Gap

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.

Dynamic Analysis of Multi-Supported Nonlinear Vibration Isolation System Mounted on Flexible Foundation

2013 ◽  
Vol 419 ◽  
pp. 223-227 ◽  
Author(s):  
Rui Huo ◽  
Hui Yu ◽  
Yan Feng Guan
Keyword(s):  
Numerical Solution ◽  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Engineering Application ◽  
System Dynamic ◽  
Dynamic Equations ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Flexible Foundation

In view of its prototype in engineering application, a theoretical model of multi-supported nonlinear vibration isolation system installed on flexible foundation is studied, including derivation of system dynamic equations and analysis of system dynamic characteristics. For effectiveness evaluation of nonlinear vibration isolation systems, a generalized time-averaged power is proposed as an extension of classical theory of vibratory power flow, and a numerical solution method of time-averaged power is probed accompanying with the numerical solution of nonlinear dynamic equations. In a further concrete calculation example, an air spring vibration isolation system of a small UAV engine is numerically simulated based on Runge-Kutta method, and dynamic behavior and power flow transmission characteristics influenced by system parameters are investigated.

Controllable electromagnetic negative stiffness spring for vibration isolator: Design, analyses and experimental verification

2020 ◽  
pp. 1-22
Author(s):  
Kai Meng ◽  
Yong Gu ◽  
Jianhui Ma ◽  
Xidong Liu ◽  
Xiangqian Geng ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Permanent Magnets ◽  
Structural Parameters ◽  
Negative Stiffness ◽  
Axial Stiffness ◽  
Isolation System ◽  
Exciting Current ◽  
Circular Current ◽  
Design Analyses ◽  
The Mathematical Model

In this study, a novel negative stiffness spring is developed. The developed spring possesses the characteristics of the controllable stiffness and can be employed in vibration isolation system with a low resonance frequency. The controllable electromagnetic negative stiffness spring (CENSS) is obtained by the coaxial permanent magnets (PMs) and the circular current-carrying coils. The stiffness control is accomplished by changing the current in the coils. Furthermore, the mathematical model of CENSS is established, based on the filament method. According to the model, the relationship between the exciting current and the axial stiffness is obtained. Moreover, the influence of the structural parameters of CENSS on the magnetic force and the stiffness is analyzed. The results demonstrate that the thickness of PMs and the coils have the ability to adjust the range of the negative stiffness. Finally, performance experimental study of CENSS in the stiffness domain is carried out under different exciting currents and thicknesses. The experimental results have shown a good agreement with the model. It demonstrates that the performance of negative stiffness in CENSS can be controlled efficiently by the exciting current and optimized by the thickness.

Dynamic Analysis of Nonlinear Vibration Isolation System Based on Flexible Foundation

2014 ◽  
Vol 1030-1032 ◽  
pp. 766-769
Author(s):  
Shu Ying Li ◽  
Rui Huo ◽  
Xing Ke Cui ◽  
Cui Ping Liu ◽  
Dao Kun Zhang
Keyword(s):  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Coupled System ◽  
Optimized Design ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Flexible Foundation

In this paper,a general dynamic model of the isolation coupled system which is composed of isolation object,nonlinear vibration isolation support,and flexible foundation is established,calculated method of applying vibration power flow to analyze isolation effectiveness is studied.Further more,as an calculation example,a air spring vibration isolation system of HS-700 engines is numerically simulated.Designs several low-frequency nonlinear vibration isolators and analyzes its vibration isolation effect.It discusses the effect of the vibration isolator parameters on the transmitted power flow of the system.The results provide a theoretical basis for the optimized design of nonlinear vibration isolation system.

Dynamic Analysis of Bionic Vibration Isolation Platform Based on Viscoelastic Materials

2014 ◽  
Vol 852 ◽  
pp. 467-471
Author(s):  
Hong Qing Lv ◽  
Wei Xiao Tang ◽  
Qing Hua Song
Keyword(s):  
Vibration Isolation ◽  
Excitation Frequency ◽  
Viscoelastic Damper ◽  
Physical Damage ◽  
Isolation System ◽  
Rubber Layer ◽  
Environmental Vibration ◽  
Performance Deterioration ◽  
Nonlinear Dynamics Model ◽  
Stiffness And Damping

The ecological structures of some organisms that could resist environmental vibration naturally (such as dragonfly, woodpecker and legs of cursorial animals) uncovered by biologists inspire people a new approach to overcome the above problem. In this paper, a new shock isolation system consisting of a pedestal, a rubber layer, an air spring and a shearing viscoelastic damper is designed, fabricated, and characterized to avoid the performance deterioration and physical damage of mechanical manufacturing devices from external mechanical excitations. The nonlinear dynamics model of the platform is developed and the dynamic characteristics are analyzed using numerical analysis. The displacement and velocity response are obtained. The results demonstrate that the stiffness and damping characteristic of the platform change with excitation frequency. The vibration isolation effectiveness will be greatly enhanced.

Vibration Isolation Characteristics of Euler Strut Spring Used in Low Frequency Vibration Isolation System

2012 ◽  
Vol 248 ◽  
pp. 475-480
Author(s):  
Guan Jun Zhang ◽  
Xiang Zhu ◽  
Ran Xu ◽  
Tian Yun Li
Keyword(s):  
Vibration Isolation ◽  
Structural Parameters ◽  
Low Frequency ◽  
Resonant Frequencies ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Low Frequency Vibration ◽  
Steel Material ◽  
Internal Resonant ◽  
Spring Maximum

Recently, the Euler strut is used as the supporting spring in the low frequency isolation. An Euler spring is a column or strut of steel material which is compressed elastically beyond its buckling load, which makes the ratio of the isolated mass to the mass of the supporting spring maximum, and greatly increasing the internal resonant frequencies of the isolator. In this research, the unique mechanical properties and the expressions of the displacement transmissibility of the Euler strut are deduced. The influences of structural parameters of the strut on the stiffness and vibration isolation characteristics are investigated in detail. The results show that the Euler strut has the potential in low frequency vibration isolation, and the length and breadth of the strut can influence the stiffness, transmissibility and critical loading mass respectively.

Sign in / Sign up

Export Citation Format

Share Document