Experimental Investigation on Damping Characteristics in Pump-Sand Box-Isolation System

2014 ◽  
Vol 1051 ◽  
pp. 906-909
Author(s):  
Xiang Jun Kong ◽  
Chong Zheng Chen
Keyword(s):  
Particle Size ◽  
Vibration Isolation ◽  
Influence Factor ◽  
Damping Ratio ◽  
Particle Packing ◽  
Initial Displacement ◽  
Isolation System ◽  
Damping Characteristics ◽  
Sand Box ◽  
Particle Damping

Sand is used in the pump-sand box-isolation system, studying the initial displacement, particle size and packing rate how to affect the damping ratio by free vibration experiments. The result shows that the initial displacement of the system has less effect on damping ratio, the particle packing rate is a significant influence factor of damping ratio, selecting the appropriate particle packing rate can get the maximum damping ratio, reducing the particle size can increase the system damping ratio, but the damping ratio no longer obviously changes when the particle size of is less than 1.5mm. In general, the packing rate needs to be controlled at below 70% in metal spring or rubber isolator system. This result can provide the basis for the design of particle damping vibration isolation system.

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.

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.

Force transmissibility of floating raft systems with quasi-zero-stiffness isolators

2017 ◽  
Vol 24 (16) ◽  
pp. 3608-3616 ◽  
Author(s):  
Li Yingli ◽  
Xu Daolin
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Low Frequency ◽  
Frequency Region ◽  
Mass Ratio ◽  
Isolation System ◽  
Floating Raft ◽  
Highly Nonlinear ◽  
Vibration Attenuation ◽  
Force Transmissibility

In view of the excellent performance of a single quasi-zero-stiffness (QZS) device in vibration attenuation, this paper presents a study on a vibration isolation floating raft system constructed with a double-layer QZS mechanism. A QZS device is a typical nonlinear isolator, hence the floating raft system is a coupled highly nonlinear isolation system. To understand the behaviors and its performance in vibration attenuation, an analytical approach is developed to describe the characteristics including the mathematical relationship between amplitude–frequency, force transmissibility, and the effects of the mass ratio and damping ratios on attenuation performance. The outcomes show that the two-degree-of-freedom QZS–QZS system is superior for vibration isolation when compared to the traditional linear system and the two other types of QZS systems. The effective vibration isolation frequency region of the QZS–QZS system is expanded to the low-frequency region by 72%. The QZS system is sensitive to the damping ratio, which decreases the resonance peak significantly. The mass ratio is a crucial design parameter in low-frequency vibration isolation design.

An efficient method for estimating the damping ratio of a vibration isolation system

2020 ◽  
Vol 21 (1) ◽  
pp. 103 ◽  
Author(s):  
Qiang Yu ◽  
Dengfeng Xu ◽  
Yu Zhu ◽  
Gaofeng Guan
Keyword(s):  
Efficient Method ◽  
Vibration Isolation ◽  
Damping Ratio ◽  
Resonance Peak ◽  
Estimation Methods ◽  
Mathematical Relationship ◽  
Isolation System ◽  
Vibration Isolation System ◽  
At Resonance ◽  
Practical Engineering

As the damping ratio determines the response of a vibration isolation system at resonance, it is very necessary to estimate the damping ratio quickly and economically for an evaluation of the effectiveness to adjust the damping in practical engineering applications. An efficient method named the “ζ-Tr” method with the characteristics of simple operation and a high accuracy is introduced to estimate the damping ratio in this paper. According to the transmissibility curve, the specific mathematical relationship in which the value of the resonance peak corresponds to the value of the damping ratio is analysed theoretically. In this case, the recognition of the resonance peak can be used to directly estimate the damping ratio without an approximation or simplification. The “ζ-Tr” method is faster, more accurate and less costly than other estimation methods. Finally, the correctness of the “ζ-Tr” method is verified by a simulation and an experiment.

Vibration Reduction of Water Source Heat Pump Units Based on Particle Damping Materials

2012 ◽  
Vol 532-533 ◽  
pp. 220-223
Author(s):  
Zi Qiang Sun ◽  
Chang Zheng Chen ◽  
Huang Liu
Keyword(s):  
Heat Pump ◽  
Vibration Isolation ◽  
Low Cost ◽  
Vibration Reduction ◽  
Low Frequency ◽  
Water Source ◽  
Isolation System ◽  
Vibration Isolators ◽  
Particle Damping ◽  
Damping Materials

Spring vibration isolators and rubber damping vibration isolators are often used in active isolation engineering of water source heat pump units. The method is inefficient in shock and low frequency vibration isolation. Because the stiffness of equipments reduces with the isolation system the vibration severity itself becomes too big for working safely. Particle damping materials can absorb vibration energy to reduce vibration. The paper testifies that successful application of particle damping materials in vibration reduction of water source heat pump units is a practical simple way with low cost.

Identification of a Nonlinear Vibration System Using Simulated Annealing, Genetic Algorithm and Programming

1999 ◽  
Author(s):  
Lubomir Sláma ◽  
Mojmir Balátě ◽  
Jiří Krejsa ◽  
Jan Slavík
Keyword(s):  
Genetic Algorithm ◽  
Simulated Annealing ◽  
Genetic Programming ◽  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Vibration System ◽  
Isolation System ◽  
Simulated Annealing Genetic Algorithm ◽  
Damping Characteristics ◽  
Nonlinear Vibration System

Abstract Application of genetic algorithm and genetic programming to identification of a nonlinear vibration system is presented. Both the theoretical groundwork and experimental results are included. The genetic algorithm is used for identification of parameters of nonlinear stiffness and friction damping characteristics of a single-degree-of-freedom model of a vibration isolation system. The genetic programming is used for identification of a functional form and parameters of a load-deflection characteristic of a rubber isolator. Obtained results from computational experiments are presented and discussed. Results of GA are compared to results obtained by using a simulated annealing method.

scholarly journals The transmissibility of a vibration isolation system with ball-screw inerter based on complex mass

2018 ◽  
Vol 37 (4) ◽  
pp. 1097-1108 ◽  
Author(s):  
Huabing Wen ◽  
Junhua Guo ◽  
Yang Li ◽  
Yue Liu ◽  
Kun Zhang
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Experimental Tests ◽  
Experimental Results ◽  
Ball Screw ◽  
Type Ii ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Complex Mass ◽  
Isolation Systems

The wide application of the ball-screw inerter for vibration isolation has made it increasingly important to precisely determine the vibration transmissibility of the isolation system. In this reported work, the transmissibility of a vibration isolation system containing an inerter was predicted by using a complex mass M* in the calculations. The reported theoretical analysis showed that in the design of the type II inerter-spring-damper and inerter-rubber vibration isolation systems, the inertance-mass ratio must be less than twice the damping ratio to achieve improved vibration isolation performance when designing the system. To validate the findings, experimental tests were conducted on the type II inerter-spring-damper and inerter-rubber vibration isolation systems with ball-screw inerter. The experimental results showed that, based on M*, the transmissibility of these two systems was close to the experimental results, which illustrated the rationale for using M*. The results of this reported study will help facilitate the parameter design and performance analysis of a vibration isolation system with an inerter.

Vibration Isolation With Nonlinear Damping

1971 ◽  
Vol 93 (2) ◽  
pp. 627-635 ◽  
Author(s):  
Jerome E. Ruzicka ◽  
Thomas F. Derby
Keyword(s):  
Relative Velocity ◽  
Vibration Isolation ◽  
Damping Ratio ◽  
Nonlinear Damping ◽  
System Response ◽  
Viscous Damping ◽  
Damping Force ◽  
Isolation System ◽  
Equivalent Viscous Damping ◽  
Arbitrary Power

This paper discusses the performance characteristics of single degree-of-freedom vibration isolation systems in which the isolator damping force is proportional to the relative velocity across the isolator raised to an arbitrary power. The concept of equivalent viscous damping is employed to develop a general equation for the equivalent viscous damping ratio which is used to determine approximate isolation system response parameters. A range of isolator damping nonlinearity is studied by varying the relative velocity exponent between 0.5 and 5 for a fixed value of damping. Detailed results for parametric variations in damping are presented for specific values of the relative velocity exponent that correspond to Coulomb, viscous, quadratic, and cubic damping mechanisms.

Application of Energy Method for Determining Loss Factor in Dynamic Systems with Hysteretic Damping

2014 ◽  
Vol 580-583 ◽  
pp. 2978-2982
Author(s):  
Vladimir Smirnov ◽  
Vladimir Mondrus
Keyword(s):  
Energy Method ◽  
Loss Factor ◽  
Seismic Isolation ◽  
Vibration Isolation ◽  
Damping Ratio ◽  
Experimental Investigations ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Hysteretic Damping ◽  
Different Types

The article studies the energy method for determining loss factor due to hysteretic damping in systems of vibration and seismic isolation. Typical measure of damping is, where φ is the phase angle between stress and strain sinusoids [1], or damping constant δ ( [2, 3]). Both of these parameters are acquired through experimental investigations for each type of boundary conditions or element’s cross section. Proposed energy method is capable of loss factor ψ determination for different types of beams based on only one experimental investigation. This method is used in the paper to determine the damping ratio of elastic element in vibration isolation system of precision equipment.

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