Design and analysis of a vibration isolation system with cam–roller–spring–rod mechanism

2021 ◽  
pp. 107754632110005
Author(s):  
Yonglei Zhang ◽  
Guo Wei ◽  
Hao Wen ◽  
Dongping Jin ◽  
Haiyan Hu
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Experimental Studies ◽  
Excitation Amplitude ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Stiffness Characteristic ◽  
Negative Stiffness Mechanism ◽  
Isolation Systems ◽  
Vibration Isolation Performance

The vibration isolation system using a pair of oblique springs or a spring-rod mechanism as a negative stiffness mechanism exhibits a high-static low-dynamic stiffness characteristic and a nonlinear jump phenomenon when the system damping is light and the excitation amplitude is large. It is possible to remove the jump via adjusting the end trajectories of the above springs or rods. To realize this idea, the article presents a vibration isolation system with a cam–roller–spring–rod mechanism and gives the detailed numerical and experimental studies on the effects of the above mechanism on the vibration isolation performance. The comparative studies demonstrate that the vibration isolation system proposed works well and outperforms some other vibration isolation systems.

scholarly journals Vibration Isolation System with Kalman Filter Estimated Acceleration Feedback: An Approach of Negative Stiffness Control

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mhia Md Zaglul Shahadat ◽  
Takeshi Mizuno ◽  
Masaya Takasaki ◽  
Fazlur Rashid ◽  
Yuji Ishino
Keyword(s):  
Kalman Filter ◽  
Vibration Isolation ◽  
Ground Vibration ◽  
Negative Stiffness ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Acceleration Feedback ◽  
Low Stiffness ◽  
Negative Stiffness Mechanism ◽  
Isolation Systems

This paper presents the isolation of vibration through the acceleration feedback of the Kalman filter. In this paper, vibration isolation was analyzed both analytically and experimentally through the estimation of the Kalman filter (KF). A negative stiffness mechanism was used to reduce the level of vibration for the developed dynamic system. The technique of negative stiffness can provide stiffness of infinite level to low stiffness as well as disturbance generated by the ground vibration directly. The performance of an isolation system through a mechanism of negative stiffness was improved by the addition of acceleration feedback. Acceleration was measured using a microelectromechanical (MEMS) type accelerometer instead of traditional servo type accelerometers due to lower cost. However, the output of a microelectromechanical (MEMS) type accelerometer is usually noisy. To avoid this difficulty, an acceleration that was estimated by a Kalman filter was considered in the acceleration feedback instead of directly measured acceleration. The dynamic behaviors of the system were compared for both the Kalman-filtered acceleration and the directly measured acceleration feedback. It is observed that the former has a significant effect on the improvement of the characteristics of the vibration isolation systems than later.

scholarly journals Design, Experiment, and Improvement of a Quasi-Zero-Stiffness Vibration Isolation System

2020 ◽  
Vol 10 (7) ◽  
pp. 2273 ◽  
Author(s):  
Shuai Wang ◽  
Wenpen Xin ◽  
Yinghao Ning ◽  
Bing Li ◽  
Ying Hu
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Excitation Amplitude ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Linear Spring ◽  
Isolation Effects ◽  
Magnetic Rings ◽  
The Relationship ◽  
Force Displacement

This paper proposes a new kind of quasi-zero-stiffness (QZS) isolation system that has the property of low-dynamic but high-static stiffness. The negative stiffness was produced using two magnetic rings, the magnetization of which is axial. First, the force–displacement characteristic of the two coupled magnetic rings was developed and the relationship between the parameters of the magnetic rings and the stiffness of the system was investigated. Then, the dynamic response of the QZS was analyzed. The force transmissibility of the system was calculated and the effects of the damping ratio and excitation amplitude on the isolation performance were investigated. The prototype of the QZS system was developed to verify the isolation effects of the system based on a comparison with a linear vibration isolation platform. Lastly, the improvement of the QZS system was conducted based on changing the heights of the ring magnets and designing a proper non-linear spring. The analysis shows the QZS system after improvement shows better isolation effects than that of the non-improved system.

Numerical Study on the Application of Chaos in Line Spectrum Reduction

2009 ◽  
Author(s):  
Jingjun Lou ◽  
Shijian Zhu
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Numerical Study ◽  
Excitation Amplitude ◽  
Point Of View ◽  
Line Spectrum ◽  
Chaotic State ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Two Degree Of Freedom

The application of chaos method in line spectrum reduction is numerically studied. The nonlinear dynamics and the power flow transmissibility of a two-degree-of-freedom vibration isolation system with nonlinear spring are analyzed. The dynamic behavior distribution chart of the system is obtained. Cascades of bifurcation of the system with different excitation amplitude are also gained. The isolation effectiveness is analyzed from the point of view of energy. The numerical results show that the reduction of the line spectrum in chaotic state is much greater than that in non-chaotic state.

scholarly journals Experimental Validation of Fly-Wheel Passive Launch and On-Orbit Vibration Isolation System by Using a Superelastic SMA Mesh Washer Isolator

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Seong-Cheol Kwon ◽  
Mun-Shin Jo ◽  
Hyun-Ung Oh
Keyword(s):  
Vibration Isolation ◽  
Application Form ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Static Tests ◽  
Resolution Observation ◽  
Passive Vibration Isolation ◽  
Basic Characteristics ◽  
Vibration Isolation Performance ◽  
Isolation Performance

On-board appendages with mechanical moving parts for satellites produce undesirable micro-jitters during their on-orbit operation. These micro-jitters may seriously affect the image quality from high-resolution observation satellites. A new application form of a passive vibration isolation system was proposed and investigated using a pseudoelastic SMA mesh washer. This system guarantees vibration isolation performance in a launch environment while effectively isolating the micro-disturbances from the on-orbit operation of jitter source. The main feature of the isolator proposed in this study is the use of a ring-type mesh washer as the main axis to support the micro-jitter source. This feature contrasts with conventional applications of the mesh washers where vibration damping is effective only in the thickness direction of the mesh washer. In this study, the basic characteristics of the SMA mesh washer isolator in each axis were measured in static tests. The effectiveness of the design for the new application form of the SMA mesh washer proposed in this study was demonstrated through both launch environment vibration test at qualification level and micro-jitter measurement test which corresponds to on-orbit condition.

Recent Advances in Quasi-Zero-Stiffness Vibration Isolation Systems

2013 ◽  
Vol 397-400 ◽  
pp. 295-303 ◽  
Author(s):  
Fu Niu ◽  
Ling Shuai Meng ◽  
Wen Juan Wu ◽  
Jing Gong Sun ◽  
Wei Hua Su ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Low Frequency ◽  
Future Research ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Significant Development ◽  
Recent Advances ◽  
Low Frequency Vibration ◽  
Future Research Directions ◽  
Isolation Systems

The quasi-zero-stiffness vibration isolation system has witnessed significant development due to the pressing demands for low frequency and ultra-low frequency vibration isolation. In this study, the isolation theory and the characteristic of the quasi-zero-stiffness vibration isolation system are illustrated. Based on its implementation mechanics, a comprehensive assessment of recent advances of the quasi-zero-stiffness vibration isolation system is presented. The future research directions are finally prospected.

A Bidirectional-Controllable Magnetorheological Energy Absorber for Shock and Vibration Isolation Systems

2012 ◽  
Author(s):  
Xian-Xu Bai ◽  
Norman M. Wereley ◽  
Wei Hu ◽  
Dai-Hua Wang
Keyword(s):  
Mechanical Model ◽  
Vibration Isolation ◽  
Dynamic Force ◽  
Damping Force ◽  
Isolation System ◽  
Isolation Systems ◽  
Force Range ◽  
Fail Safe ◽  
Safe Performance ◽  
Vibration Isolation Performance

Semi-active shock and vibration isolation systems using magnetorheological energy absorbers (MREAs) require minimization of the field-off damping force at high speed. This is because the viscous damping force for high shaft speed become excessive. This implies that the controllable dynamic force range, defined as the ratio of the field-on damping force to the field-off damping force, is dramatically reduced. In addition, fail-safe MREA performance, if power were to be lost, is of great importance to shock and vibration isolation systems. A key design goal is to minimize field-off damping force while maximizing MREA dynamic force, while maintaining fail-safe performance. This study presents the principle of a bidirectional-controllable MREA that can produce large damping force and dynamic force range, as well as excellent fail-safe performance. The bidirectional-controllable MREA is configured and its hydro-mechanical model is theoretically constructed. From the hydro-mechanical model, the mathematical model for the MREA is established using a Bingham-plastic nonlinear fluid model. The characteristics of the MREA are theoretically evaluated and compared with those of a conventional flow-mode MREA with an identical volume. In order to investigate the feasibility and capability of the bidirectional-controllable MREA in the context of the semi-active shock and vibration isolation systems, a mechanical model of a single-degree-of-freedom (SDOF) isolation system using a bidirectional-controllable MREA is constructed and the governing equation for the SDOF isolation system is derived. A skyhook control algorithm is utilized to improve the shock and vibration isolation performance of the isolation systems. Simulated vibration isolation performance using bidirectional-controllable and conventional MREAs under shock loads due to vertical impulses (the initial velocity is as high as 10 m/s), and sinusoidal vibrations, are evaluated, compared, and analyzed.

scholarly journals High-Efficiency Vibration Isolation for a Three-Phase Power Transformer by a Quasi-Zero-Stiffness Isolator

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hao Cao ◽  
Yaopeng Chang ◽  
Jiaxi Zhou ◽  
Xuhui Zhao ◽  
Ling Lu ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
High Efficiency ◽  
Power Transformer ◽  
Dynamic Stiffness ◽  
Harmonic Balance Method ◽  
Isolation System ◽  
Three Phase ◽  
Engineering Practices ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The vibrations generated by a three-phase power transformer reduce the comfort of residents and the service life of surrounding equipment. To resolve this tough issue, a quasi-zero-stiffness (QZS) isolator for the transformer is proposed. This paper is devoted to developing a QZS isolator in a simple way for engineering practices. The vertical springs are used to support the heavy weight of the transformer, while the oblique springs are employed to fulfill negative stiffness to neutralize the positive stiffness of the vertical spring. Hence, a combination of the vertical and oblique spring can yield high static but low dynamic stiffness, and the vibration isolation efficiency can be improved substantially. The dynamic analysis for the QZS vibration isolation system is conducted by the harmonic balance method, and the vibration isolation performance is estimated. Finally, the prototype of the QZS isolator is manufactured, and then the vibration isolation performance is tested comparing with the linear isolator under real power loading conditions. The experimental results show that the QZS isolator prominently outperforms the existing linear isolator. This is the first time to devise a QZS isolator for three-phase power transformers with heavy payloads in engineering practices.

scholarly journals STUDY OF VIBRATION ISOLATION SYSTEM OF AGRICULTURAL POWER UNITS WITH HYDRAULIC VIBRATION MOUNTS

2021 ◽  
pp. 111-116
Author(s):  
V.V. Kovalev ◽  
Keyword(s):  
Vibration Isolation ◽  
Isolation System ◽  
Agricultural Vehicles ◽  
Vibration Isolation System ◽  
Existing Structures ◽  
Suspension Systems ◽  
Urgent Task ◽  
Fixed Base ◽  
Isolation Systems ◽  
Agricultural Machines

At the present, the improvement of vibration isolation systems for equipment, machines and units remains an urgent task. The ways to solve this problem are based on the optimization of existing structures, the development and application of new vibration-insulating elements as well as the improvement of design methods. In particular, to ensure the reliable functioning of agricultural machines, units, working elements and other mechanization means for the technological processes of agricultural production one of the perspective areas is the use of hydraulic vibra-tion mounts in suspension systems for units. This type of mounts is used to mount engines, cabins of agricultural vehicles, and power units. This paper discusses the simu-lation of the dynamic behavior of a power unit attached to a fixed base by the hydraulic mounts. It is proposed to use approximating functions modelling real stiffness character-istics of the mounts. A comparative analysis with a similar design using rubber-metal mounts as vibration-insulating elements is presented.

Design of a vibration isolation system using eddy current damper

2013 ◽  
Vol 228 (4) ◽  
pp. 664-675 ◽  
Author(s):  
Partha Paul ◽  
Chetan Ingale ◽  
Bishakh Bhattacharya
Keyword(s):  
Eddy Current ◽  
Vibration Isolation ◽  
Eddy Currents ◽  
High Efficiency ◽  
Experimental Studies ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Analysis And Design ◽  
Passive Vibration Isolation ◽  
Eddy Current Damper

This article aims at modeling, analysis and design of a passive vibration isolation system using a magnetic damper with high efficiency and compactness. The experimental set-up was developed for a single degree-of-freedom vibration isolation system, where the damper consists of two elements: an outer stationary conducting tube made up of copper and a moving core made up of an array of three ring-shaped neodymium magnets of Nd–Fe–B alloy separated by four block cylinders made of mild steel that are fixed to a steel rod. The generation of eddy currents in the conductor and its resistance causes the mechanical vibration to dissipate heat energy. The vibration response of the system is obtained starting from a low-frequency range. The proposed magnetic damper achieves a maximum transmissibility value less than two for a natural frequency that is less than 10 Hz and the excitations at higher frequencies are successfully isolated. Numerical and experimental studies were carried out for a range of system parameters which show that isolators based on magnetic damping could be very effective for passive vibration isolation. Further, a theoretical model for an active isolation system is proposed in order to reduce the transmissibility at resonance. It is envisaged that the combined active–passive eddy current damper could be effectively used for vibration isolation.

A Modular-Type Three-Axis Vibration Isolation System Using Negative Stiffness

2010 ◽  
Author(s):  
Md. Emdadul Hoque ◽  
Takeshi Mizuno ◽  
Yuji Ishino ◽  
Masaya Takasaki
Keyword(s):  
Vibration Isolation ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Negative Stiffness ◽  
Isolation System ◽  
Single Degree Of Freedom ◽  
Vibration Isolation System ◽  
Single Degree ◽  
In Series ◽  
Isolation Systems

A vibration isolation system is presented in this paper which is developed by the combination of multiple vibration isolation modules. Each module is fabricated by connecting a positive stiffness suspension in series with a negative stiffness suspension. Each vibration isolation module can be considered as a self-sufficient single-degree-of-freedom vibration isolation system. 3-DOF vibration isolation system can be developed by combining three modules. As the number of motions to be controlled and the number of actuators are equal, there is no redundancy in actuators in such vibration isolation systems. Experimental results are presented to verify the proposed concept of the development of MDOF vibration isolation system using vibration isolation modules.

Sign in / Sign up

Export Citation Format

Share Document