Research on linear/nonlinear viscous damping and hysteretic damping in nonlinear vibration isolation systems

2020 ◽  
Vol 41 (7) ◽  
pp. 983-998
Author(s):  
Zhong Zhang ◽  
Muqing Niu ◽  
Kai Yuan ◽  
Yewei Zhang
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Viscous Damping ◽  
Hysteretic Damping ◽  
Isolation Systems

Vibration Analysis of Nonlinear Isolator’s Characteristics by ADAMS

2012 ◽  
Vol 152-154 ◽  
pp. 1077-1081 ◽  
Author(s):  
Zhao Qi He ◽  
Yu Chao Song ◽  
Hong Liang Yu
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Excitation Frequency ◽  
Vibration Isolator ◽  
Vibration System ◽  
Linear Vibration ◽  
External Excitation ◽  
Mass Model ◽  
Adams Software ◽  
Isolation Systems

A nonlinear spring-mass model is established to study the dynamic characteristics of nonlinear vibration isolator. By use of ADAMS software, the influence of stiffness, foundation displacement excitation and frequency of external excitation on the nonlinear vibration isolation systems are analyzed. Results indicate that the linear vibration system needs 4s to achieve stability, but the nonlinear vibration system only needs 0.1s. The response value increases with the increase of excitation frequency, the response pick value increases by 61.58% and 102.35% and each corresponding stable value increases by 159.35% and 309.87%.

scholarly journals Dynamic analysis and experiment of QZS system with nonlinear hysteretic damping

2021 ◽  
Author(s):  
Xiaoying Hu ◽  
Chunyan Zhou
Keyword(s):  
Vibration Isolation ◽  
Harmonic Balance Method ◽  
Nonlinear Damping ◽  
Primary Response ◽  
Nonlinear Phenomena ◽  
Isolation Frequency ◽  
Hysteretic Damping ◽  
Isolation Systems ◽  
The One ◽  
Vibration Tests

Abstract Nonlinear Quasi-zero-stiffness (QZS) vibration isolation systems with linear damping cannot lead to displacement isolation with different excitation levels. In this study, a QZS system with nonlinear hysteretic damping was investigated. The Duffing-Ueda equation with a coupling nonlinear parameter 𝜂 was proposed to describe the dynamic motion of the QZS system. By using the harmonic balance method (HBM), the primary and secondary harmonic responses were obtained and verified by numerical simulations. The results indicated that nonlinear damping can guarantee a bounded response for different excitation levels. The one-third subharmonic response was found to affect the isolation frequency range even when the primary response was stable. To evaluate the performance of the QZS system, the effective isolation frequency Ω𝑒 and maximum transmissibility 𝑇𝑝 were proposed to represent the vibration isolation range and isolation effect, respectively. By discussing the effect of 𝜂 on Ω𝑒 and 𝑇𝑝, the conditions to avoid nonlinear phenomena and improve the isolation performance are provided. A prototype of the QZS system was then constructed for vibration tests, which verified the theoretical analysis.

Nonlinear Vibration Characteristics of Fatigue Damaged Reinforced Concrete Structures

2005 ◽  
Vol 297-300 ◽  
pp. 2592-2597
Author(s):  
Jin Ho Kim
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Concrete Structures ◽  
Analytical Models ◽  
Fatigue Properties ◽  
Reinforced Concrete Structures ◽  
Isolation System ◽  
Discrete Crack ◽  
Isolation Systems

In this paper, nonlinear vibration techniques were applied to investigate stages of progressive damage in three vibration isolation systems induced by dynamic loadings. Analytical models for reinforced concrete structures of three isolation systems were developed based on FEM with discrete crack concept. Vibration response spectra and the spectra of forces transmitted through the isolators were computed with respect to stationary dynamic loads. In addition, fatigue properties of concrete structures were examined for given materials’ properties and given geometries. The results indicated that the proposed isolation system 3 can improve fatigue resistance by extending fatigue life and changing the failure mode from shear to flexure.

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.

A Resonance Chart for Damped Vibration

1955 ◽  
Vol 59 (540) ◽  
pp. 850-852 ◽  
Author(s):  
R. E. D. Bishop
Keyword(s):  
Linear System ◽  
Convenient Method ◽  
Harmonic Excitation ◽  
Degree Of Freedom ◽  
Viscous Damping ◽  
Similar Form ◽  
Hysteretic Damping ◽  
Resonance Curves ◽  
Phase Angles

A convenient method is pointed out for calculating the response of a damped linear system with one degree of freedom to harmonic excitation. Results of such calculations are usually represented by the familiar “ resonance curves ”—one curve being plotted for each intensity of damping. These curves are not particularly convenient to use and Yates has overcome several of their defects by throwing them into a nomographic form. Yates' nomogram is based upon the concept of viscous damping and it does not give the information of a conventional set of resonance curves in that it relates to the velocity of vibration. By changing over to hysteretic damping, a nomogram of somewhat similar form may be constructed such that it gives amplitudes and phase angles of displacements while retaining the advantages, over resonance curves, of this form of representation.

Structural analysis of the trajectories of random processes formed in non-linear vibration isolation systems

2021 ◽  
Author(s):  
A.S. Gusev ◽  
L.V. Zinchenko ◽  
S.A. Starodubtseva
Keyword(s):  
Structural Analysis ◽  
Vibration Isolation ◽  
Fundamental Principle ◽  
Statistical Dependence ◽  
Absolute Maximum ◽  
Time Interval ◽  
Apparent Lack ◽  
The Road ◽  
Isolation Systems ◽  
Non Gaussian

When designing technical structures, the safety of their elements is a fundamental principle. This highlights the significance of the proposed solution to the structural analysis of the trajectories of non-Gaussian stationary processes. The solution aims to acquire source data for calculating the stress-strength reliability of structural elements operating under random loads. We analyze an approach that makes it possible to account for the statistical dependence between processes and their derivatives, despite the apparent lack of correlation between them. The considered approach can be utilized in the design of vibration protection of transport vehicles to calculate the probability of a shock absorber breakdown, the probability of loss of the road-wheel contact, etc. The operation reliability of such systems is defined as the probability that the absolute maximum of the process does not exceed the specified standard level during a certain time interval. The article presents the reliability calculation using structural analysis on the example of a one-dimensional stochastic system.

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