Analysis of Axial Vibration in the Laminated Rubber-Metal Spring

2013 ◽  
Vol 845 ◽  
pp. 46-50 ◽  
Author(s):  
Mohd Azli Salim ◽  
Azma Putra ◽  
Mohd Azman Abdullah
Keyword(s):  
High Frequency ◽  
Axial Direction ◽  
Vibration Isolator ◽  
Axial Vibration ◽  
Parameter System ◽  
Internal Resonances ◽  
Lumped Parameter ◽  
Metal Plates ◽  
Vibration Transmissibility ◽  
Earthquake Protection

The laminated rubber-metal spring is well known in application as the vibration isolator for earthquake protection. The spring is therefore designed to be able to sustain the vibration waves from horizontal direction. This paper discusses the possibility of the laminated spring to be employed for other applications where the excitation mainly comes from axial direction, such as to isolate vibration transmission from heavy engine. The model is first developed for a simple finite rod to simulate the effect of internal resonances at high frequency when the wavelength is much smaller than the length of the rod. The effect of metal plates inserted in the rubber is then modelled using the lumped parameter system. The results are presented in terms of the vibration transmissibility.

Modeling of Mullins Effect on Laminated Rubber-Metal Spring

2014 ◽  
Vol 699 ◽  
pp. 331-335 ◽  
Author(s):  
Mohd Azli Salim ◽  
Mohd Azman Abdullah ◽  
Azma Putra
Keyword(s):  
Vertical Direction ◽  
Metal Plate ◽  
Degree Of Freedom ◽  
Mullins Effect ◽  
Parameter System ◽  
Compression Load ◽  
Lumped Parameter ◽  
Metal Plates

This paper presents the Mullins effect on the laminated rubber-metal spring analytically modeled using lumped parameter system. The general form of the equation is developed to represent the multi-degree-of-freedom system for layer of embedded metal plates. The Mullins effect can be observed when a compression load is applied to the spring. It is shown that by increasing the embedded metal plate, the Mullins effect inside the rubber is reduced due to the improved stiffness in vertical direction.

Dynamic Stability of a Water Brake Dynamometer

1998 ◽  
Vol 120 (1) ◽  
pp. 89-96 ◽  
Author(s):  
R. A. Van den Braembussche ◽  
H. Malys
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Lumped Parameter Model ◽  
Stable Operation ◽  
Pressure Oscillations ◽  
Lumped Parameter ◽  
Flow Oscillations ◽  
Brake Dynamometer ◽  
Low Torque ◽  
Frequency Variations

A lumped parameter model to predict the high frequency pressure oscillations observed in a water brake dynamometer is presented. It explains how the measured low frequency variations of the torque are a consequence of the variation in amplitude of the high frequency flow oscillations. Based on this model, geometrical modifications were defined, aiming to suppress the oscillations while maintaining mechanical integrity of the device. An experimental verification demonstrated the validity of the model and showed a very stable operation of the modified dynamometer even at very low torque.

Bond Graph Sign Conventions

1975 ◽  
Vol 97 (2) ◽  
pp. 184-188 ◽  
Author(s):  
A. S. Perelson
Keyword(s):  
Graph Model ◽  
Bond Graph ◽  
Equivalence Classes ◽  
Parameter System ◽  
Bond Graphs ◽  
Lumped Parameter ◽  
Oriented Object

The lack of arbitrariness in the choice of bond graph sign conventions is established. It is shown that an unoriented bond graph may have no unique meaning and that with certain choices of orientation a bond graph may not correspond to any lumped parameter system constructed from the same set of elements. Network interpretations of these two facts are given. Defining a bond graph as an oriented object leads to the consideration of equivalence classes of oriented bond graphs which represent the same system. It is also shown that only changes in the orientation of bonds connecting 0-junctions and 1-junctions can lead to changes in the observable properties of a bond graph model.

Airway pressures in an asymmetrically branched airway model of the dog respiratory system

1984 ◽  
Vol 57 (4) ◽  
pp. 1222-1230 ◽  
Author(s):  
Andrew C. Jackson ◽  
Mehrdad Tabrizi ◽  
Michael I. Kotlikoff ◽  
Jon R. Voss
Keyword(s):  
Respiratory System ◽  
High Frequency ◽  
High Frequency Ventilation ◽  
Tissue Properties ◽  
Pressure Distributions ◽  
Lumped Parameter ◽  
Airway Opening ◽  
Frequency Ventilation ◽  
Lung Periphery ◽  
Airway Model

A computer model of the mechanical properties of the dog respiratory system based on the asymmetrically branching airway model of Horsfield et al. (11) is described. The peripheral ends of this airway model were terminated by a lumped-parameter impedance representing gas compression in the alveoli, and lung and chest wall tissue properties were derived from measurements made in this laboratory. Using this model we predicted the respiratory system impedance and the distribution of pressures along the airways in the dog lung. Predicted total respiratory system impedances for frequencies between 4 and 64 Hz at three lung volumes were found to compare quite closely to measured impedances in dogs. Serial pressure distributions were found to be frequency-dependent and to result in higher pressures in the lung periphery than at the airway opening at some frequencies. The implications of this fading for high-frequency ventilation are discussed. impedance; high-frequency ventilation; central airway resistance; respiratory system resistance; airway pressure distribution; distribution of ventilation Submitted on November 14, 1983 Accepted on May 8, 1984

scholarly journals A Vibration-Isolated Body of Chaotic Prediction

2011 ◽  
Vol 2-3 ◽  
pp. 978-983
Author(s):  
Yong Yi Gao ◽  
Shi Ping Zhan ◽  
Ban Gyan Li
Keyword(s):  
High Frequency ◽  
Simulation Experiment ◽  
Variable Parameter ◽  
Slow Variable ◽  
State Equation ◽  
Analytical Prediction ◽  
Vibration Isolator ◽  
Weak Nonlinearity ◽  
Analog Simulation ◽  
Inherent Frequency

The nonlinear dynamics equation of passive vibration isolator is established in this paper. According to the nonlinear vibration theory, the average equation of slow-varying primary harmonic in the condition of weak nonlinearity is abstained , and derived a discrete mapping of the harmonic slow variable parameter state equation, then get the analytical conditions of chaos in the passive vibration isolator, the analytical results show that only when the vibration frequency of the groundsill is higher than the inherent frequency of the passive vibration isolator, the chaos can be observed, when the groundsill vibrate with the large amplitude and high frequency vibration, the chaos can’t be observed in the passive vibration isolator system. Finally the analytical prediction is validated by analog simulation experiment, and gets the conclusion that the prediction matches well with the simulation results.

Rotation-induced axial oscillation of a composite nanoconvertor at low temperature

2020 ◽  
pp. 107754632093711
Author(s):  
Bo Song ◽  
Kun Cai ◽  
Jiao Shi ◽  
Qing-Hua Qin
Keyword(s):  
Molecular Dynamics ◽  
Low Temperature ◽  
Large Amplitude ◽  
Oscillation Amplitude ◽  
Axial Direction ◽  
Axial Vibration ◽  
Axial Oscillation ◽  
Axial Translation ◽  
Vibration Responses ◽  
Dynamics Simulations

We propose a model of a nanostructure which can transform an input rotation into an output oscillation. In the model, the rotor has two identical internally hydrogenated deformable parts. The mechanism is that the rotation-induced centrifugal force and van der Waals force drive the recoverable deformation of the hydrogenated deformable parts, which gives rise to the axial translation of the free end of the rotor. Once the two hydrogenated deformable parts deform periodically, the free end of the rotor oscillates periodically in the axial direction. Molecular dynamics simulations are conducted to reveal the dynamic response of the system at low temperature. Four main types of deformation and the first three orders of vibration responses of the hydrogenated deformable parts are analyzed. Synchronous breathing vibration of the two hydrogenated deformable parts produces ideal oscillation with large amplitude. Asynchronous axial vibration of the hydrogenated deformable parts reduces the oscillation amplitude or produces beat vibration. The way to control the amplitude of the axial oscillation/vibration is given.

Active Vibration Control and Isolation for Micro-Machined Devices

2008 ◽  
Author(s):  
Seong Jin Kim ◽  
Chen Chen ◽  
George Flowers ◽  
Robert Dean
Keyword(s):  
High Frequency ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Low Pressure ◽  
High Amplitude ◽  
Vibration Isolator ◽  
Mems Devices ◽  
Mechanical Vibrations ◽  
Mems Gyroscopes ◽  
Filter Structures

Some harsh environments contain high frequency, high amplitude mechanical vibrations. Unfortunately some very useful components, such as MEMS gyroscopes, can be very sensitive to these high frequency mechanical vibrations. Passive micromachined silicon lowpass filter structures (spring-mass-damper) have been demonstrated in recent years. However, the performance of these filter structures is typically limited by low damping. This is especially true if operated in low pressure environments, which is often the optimal operating environment for the attached device that requires vibration isolation. An active micromachined vibration isolator can be realized by combining a state sensor, and electrostatic actuator and feedback electronics with the passive isolator. Using this approach, a prototype active micromachined vibration isolator is realized and used to decrease the filter Q from approximately 135 to approximately 60, when evaluated in a low pressure environment. The physical size of these active isolators is suitable for use in or as packaging for sensitive electronic and MEMS devices, such as MEMS vibratory gyros.

scholarly journals Dynamics Analysis of Active Variable Stiffness Vibration Isolator for Whole-Spacecraft Systems Based on Nonlinear Output Frequency Response Functions

2020 ◽  
Vol 33 (6) ◽  
pp. 731-743
Author(s):  
Kefan Xu ◽  
Yewei Zhang ◽  
Yunpeng Zhu ◽  
Jian Zang ◽  
Liqun Chen
Keyword(s):  
Frequency Response ◽  
Energy Absorption ◽  
Absorption Rate ◽  
Vibration Isolation ◽  
Variable Stiffness ◽  
Response Functions ◽  
Vibration Isolator ◽  
Output Frequency ◽  
Frequency Response Functions ◽  
Vibration Transmissibility

AbstractIn order to improve the harsh dynamic environment experienced by heavy rockets during different external excitations, this study presents a novel active variable stiffness vibration isolator (AVS-VI) used as the vibration isolation device to reduce excessive vibration of the whole-spacecraft isolation system. The AVS-VI is composed of horizontal stiffness spring, positive stiffness spring, parallelogram linkage mechanism, piezoelectric actuator, acceleration sensor, viscoelastic damping, and PID active controller. Based on the AVS-VI, the generalized vibration transmissibility determined by the nonlinear output frequency response functions and the energy absorption rate is applied to analyze the isolation performance of the whole-spacecraft system with AVS-VI. The AVS-VI can conduct adaptive vibration suppression with variable stiffness to the whole-spacecraft system, and the analysis results indicate that the AVS-VI is effective in reducing the extravagant vibration of the whole-spacecraft system, where the vibration isolation is decreased up to above 65% under different acceleration excitations. Finally, different parameters of AVS-VI are considered to optimize the whole-spacecraft system based on the generalized vibration transmissibility and the energy absorption rate.

scholarly journals Analysis and Design of Helmholtz Protector to Improve High-Frequency Response of Insert Earphone

2019 ◽  
Vol 9 (12) ◽  
pp. 2541 ◽  
Author(s):  
Yuan-Wu Jiang ◽  
Dan-Ping Xu ◽  
Zhi-Xiong Jiang ◽  
Jun-Hyung Kim ◽  
Sang-Moon Hwang
Keyword(s):  
Frequency Response ◽  
High Frequency ◽  
Experimental Result ◽  
Parameter Method ◽  
Analysis Tool ◽  
Analysis Method ◽  
Analysis And Design ◽  
High Frequency Response ◽  
Lumped Parameter ◽  
Lumped Parameter Method

With the development of multimedia devices, earphones are playing an increasingly important role. This article applies the lumped parameter method using an equivalent circuit to model the electromagnetic, mechanical, and acoustic domains of earphones. Then, parameters are determined according to the dimensions and material properties of earphone parts. On the basis of the analysis tool and determined parameters, a Helmholtz protector is analyzed and designed to improve the high-frequency response. Samples are fabricated, and the experiment verifies the analysis method. The experimental result shows that the peaks at 7 k and 10 k are decreased at 8.05 dB and 7.89 dB. The root means square value of SPL deviation compared with target curve decreased from 9.77 to 4.39. High-frequency response is improved by using the Helmholtz protector.

Sign in / Sign up

Export Citation Format

Share Document