scholarly journals Some Features of Geometric Nonlinear Damping on Isolation Performance

2019 ◽  
Vol 1264 ◽  
pp. 012060
Author(s):  
G Gatti ◽  
M G Tehrani
Keyword(s):  
Nonlinear Damping ◽  
Geometric Nonlinear ◽  
Isolation Performance

Beneficial performance of a quasi-zero stiffness vibration isolator with generalized geometric nonlinear damping

2020 ◽  
pp. 095745652097238
Author(s):  
Chun Cheng ◽  
Ran Ma ◽  
Yan Hu
Keyword(s):  
Damping Ratio ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Equivalent Damping ◽  
Frequency Responses ◽  
Geometric Nonlinear ◽  
Resonant Region ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Force And Displacement Transmissibility

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

Enhanced isolation performance of a high-static–low-dynamic stiffness isolator with geometric nonlinear damping

2018 ◽  
Vol 93 (4) ◽  
pp. 2339-2356 ◽  
Author(s):  
Guangxu Dong ◽  
Yahong Zhang ◽  
Yajun Luo ◽  
Shilin Xie ◽  
Xinong Zhang
Keyword(s):  
Dynamic Stiffness ◽  
Nonlinear Damping ◽  
Geometric Nonlinear ◽  
Isolation Performance

scholarly journals Research on New Types of Suspension Vibration Reduction Systems (SVRSs) with Geometric Nonlinear Damping

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Meng Yang ◽  
Jian Zhang ◽  
Xingjiu Luo
Keyword(s):  
Differential Equations ◽  
Vibration Isolation ◽  
Vibration Reduction ◽  
Nonlinear Damping ◽  
Random Excitation ◽  
Impact Excitation ◽  
Geometric Nonlinear ◽  
Ergodic Optimization ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Firstly, this paper puts forward two new types of suspension vibration reduction systems (SVRSs) with geometric nonlinear damping based on general SVRS (GSVRS), which only has geometric nonlinear stiffness. Secondly, it derives the motion differential equations for the two new types of SVRS, respectively, and discusses the similarities and differences among the two types and GSVRS through the comparison of motion differential equations. Then, it conducts dimensionless processing of the motion differential equations for the two new types of SVRS and carries out a comparative study on the vibration isolation performance of the two types of SVRS under impact excitation and random excitation, respectively. At last, it performs the optimal computation of the chosen new type of SVRS through the ergodic optimization method and studies the influence rule of SVRS parameters on vibration isolation performance so as to realize the optimization of vibration isolation performance.

scholarly journals Analysis and design of the power law damping based on the nonlinear vessel isolation system

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881719 ◽  
Author(s):  
You Wang ◽  
Xinghua Zhu ◽  
Rong Zheng ◽  
Zhe Tang ◽  
Bingbing Chen
Keyword(s):  
Resonant Frequency ◽  
Working Conditions ◽  
Power Law ◽  
Nonlinear Damping ◽  
Frequency Region ◽  
Isolation System ◽  
Analysis And Design ◽  
Force Transmissibility ◽  
Isolation Systems ◽  
Isolation Performance

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.

Study on the force transmissibility of vibration isolators with geometric nonlinear damping

2013 ◽  
Vol 74 (4) ◽  
pp. 1103-1112 ◽  
Author(s):  
Jingya Sun ◽  
Xiuchang Huang ◽  
Xingtian Liu ◽  
Feng Xiao ◽  
Hongxing Hua
Keyword(s):  
Nonlinear Damping ◽  
Vibration Isolators ◽  
Geometric Nonlinear ◽  
Force Transmissibility

scholarly journals An Asymmetric Quasi-zero Stiffness Vibration Isolator with Long Stroke and Large Bearing Capacity

2021 ◽  
Author(s):  
Xinghua Zhou ◽  
Dingxuan Zhao ◽  
Xiao Sun ◽  
Xiao Yang ◽  
Jianhai Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Vibration Isolation ◽  
Geometrical Nonlinearity ◽  
Harmonic Balance Method ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Plate Spring ◽  
Supporting Force ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Abstract A novel passive asymmetric quasi-zero stiffness vibration isolator (AQZS-VI) comprising two linear springs acting in parallel with one negative stiffness element (NSE) is proposed, of which the NSE is mainly constructed by the combination of cantilever plate spring and L-shaped lever (CPS-LSL). The static model of the isolator is deduced considering the geometrical nonlinearity of the NSE and the bending deformation of plate spring. The nonlinear stiffness properties of the CPS-LSL and the AQZS-VI, as well as the nonlinear damping properties of the AQZS-VI are discussed. The absolute displacement transmissibility of the AQZS-VI under base displacement excitation is obtained using Harmonic Balance Method, and the effects of different excitation amplitudes and damping factors on the vibration isolation performance are analyzed. Better than other quasi-zero stiffness vibration isolators (QZS-VI) whose NSEs do not provide supporting force at zero stiffness point, the NSE of the AQZS-VI provides more supporting force than the parallel connected linear springs, which is very beneficial for improving the bearing capacity of the isolator. Compared with a typical symmetric QZS-VI with same damping property, the AQZS-VI has longer stroke with low stiffness and lower peak value of displacement transmissibility. The prototype experiments indicate that the AQZS-VI outperforms the linear counterpart with much smaller starting frequency of vibration isolation and lower displacement transmissibility. The proposed AQZS-VI has great potential for applying in various engineering practices with superior vibration isolation performance.

The Effect of Stiffness and Loading Deviations in a Nonlinear Isolator Having Quasi Zero Stiffness and Geometrically Nonlinear Damping

2017 ◽  
Author(s):  
Ata Donmez ◽  
Ender Cigeroglu ◽  
Gokhan O. Ozgen
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Nonlinear Differential Equations ◽  
Harmonic Balance Method ◽  
Nonlinear Damping ◽  
Geometrically Nonlinear ◽  
Algebraic Equations ◽  
Isolation System ◽  
Highly Nonlinear ◽  
Isolation Performance

Static deflections due to static loadings limit the isolation performance of linear vibration isolation systems. Therefore, quasi-zero stiffness (QZS) mechanisms, i.e. nonlinear isolators with high static and low dynamic stiffness characteristic, are used to decrease the natural frequency of the isolation structure and improve the isolation performance of the system while having the same loading capacity. However, the resulting system is highly nonlinear and unstable solutions may as well occur. Although increasing the amount of linear viscous damping in the system reduces the nonlinearity, it has adverse effect on the isolation region. Geometrically nonlinear damping is effective when the response of the isolation system increases; hence, isolation region is unaffected. Combination of position depended nonlinear damping and QZS mechanism eliminates highly input depended response of QZS mechanism. In this study, a single degree of freedom system with a nonlinear isolator having QZS mechanism and geometrically nonlinear damping is considered. The nonlinear differential equations of motion of the isolation system are converted into a set of nonlinear algebraic equations by using harmonic balance method, which are solved by using Newton’s method with arc-length continuation. Several case studies are performed and the effect of stiffness and loading deviations on the isolation performance is studied.

scholarly journals Passive impact/vibration control and isolation performance optimization for space noncooperative target capture

2020 ◽  
Vol 17 (1) ◽  
pp. 172988141989538
Author(s):  
Chong Sun ◽  
Xiaolei Hou
Keyword(s):  
Performance Optimization ◽  
Optimization Method ◽  
Nonlinear Damping ◽  
Isolation System ◽  
Capture Process ◽  
Target Capture ◽  
Passive Isolation ◽  
The Impact ◽  
Impact Vibration ◽  
Isolation Performance

On-orbit capture is an important technique for the space debris removal, refueling, or malfunction satellite repairing. While due to the uncertainty of the motion parameters of the space noncooperative target, the impact between the capture device and the noncooperative target during the capturing process is inevitable, which may bring strong vibration perturbation to the base satellite, and potentially alter the position and the attitude of the servicing spacecraft, or even cause failure of on-orbit tasks. This article presents a new and alternative method for passive suppression of spacecraft impact and perturbation during noncooperative spacecraft capture. The passive device based on bioinspired X-shape is installed between the satellite and the capture device. In the capture process, nonlinear damping of the passive isolation structure can significantly reduce impact/vibration perturbation. For performance analysis, dynamic equations of the isolation system are established. Based on which, the relationship between structure parameters and isolation performance is systematically analyzed. Experiments are conducted for verification of the effectiveness of the proposed method. Moreover, an optimal process using the non-dominated sorting genetic algorithm II optimization method is developed to minimize impact/vibration perturbation effect, and optimal solutions can provide useful reference for the passive isolation system design.

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