Vibration Analysis and Optimal Design for Cab’s Isolation System of Vibratory Roller

2011 ◽  
Vol 199-200 ◽  
pp. 936-940 ◽  
Author(s):  
Le Van Quynh ◽  
Jian Run Zhang ◽  
Guo Wang Jiao ◽  
Xiao Bo Liu ◽  
Yuan Wang

In recent years, vibration roller market has required increasingly not only on working capacity but also ride comfort. Thus, in order to reduce the effect of vibration to operators, identification and elimination of vibration sources are the most important tasks to achieve optimum design. In this paper, the attention is paid to cab’s low-frequency sloshing analysis and optimal design for cab’s isolation system of vibratory roller. When working, it often exists the problem of cab’s low-frequency sloshing in the direction of forward motion. In order to solve this problem, the dynamic test and simulations analysis are carried out; and the main reasons causing cab’s low-frequency sloshing are found out. The optimization model according to the two points response amplitude in the direction of forward motion on the cab to reach the minimum value in the low frequency range is proposed in this paper. And also, the auxiliary vibrations isolator for solving the low-frequency sloshing in the direction of forward motion is designed.

2018 ◽  
Vol 875 ◽  
pp. 105-112 ◽  
Author(s):  
Van Quynh Le ◽  
Khac Tuan Nguyen

In order to improve the vibratory roller ride comfort, a multi-objective optimization method based on the improved genetic algorithm NSGA-II is proposed to optimize the design parameters of cab’s isolation system when vehicle operates under the different conditions. To achieve this goal, 3D nonlinear dynamic model of a single drum vibratory roller was developed based on the analysis of the interaction between vibratory roller and soil. The weighted r.m.s acceleration responses of the vertical driver’s seat, pitch and roll angle of the cab are chosen as the objective functions. The optimal design parameters of cab’s isolation system are indentified based on a combination of the vehicle nonlinear dynamic model of Matlab/Simulink and the NSGA - II genetic algorithm method. The results indicate that three objective function values are reduced significantly to improve vehicle ride comfort.


2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110729
Author(s):  
Sangwook Kang

An advanced non-dimensional dynamic influence function method (NDIF method) for highly accurate free vibration analysis of membranes with arbitrary shapes is proposed in this paper. The existing NDIF method has the weakness of not offering eigenvalues and eigenmodes in the low frequency range when the number of boundary nodes of an analyzed membrane is increased to obtain more accurate result. This paper reveals that the system matrix of the membrane becomes singular in the lower frequency range when the number of the nodes increases excessively. Based on this fact, it provides an efficient way to successfully overcome the weaknesses of the existing NDIF method and still maintain its accuracy. Finally, verification examples show the validity and accuracy of the advanced NDIF method proposed.


Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1132
Author(s):  
Hangyuan Lv ◽  
Yimin Zhang

This paper first employs and develops an exact wave-based vibration analysis approach to investigate a finite Timoshenko beam carrying periodic two-degree-of-freedom (2-DOF) uncoupled force-moment type resonators. In the approach, vibrations are described as structural waves that propagate along uniform structural elements and reflected and transmitted at structural discontinuities. Each uncoupled force-moment type resonator is considered as a cell which injects waves into the distributed beam through the transverse force and the bending moment at the attached point. By assembling wave relations of the cells into the beam, the forced vibration problem of the locally resonant (LR) structure is turned to be the solution to a related set of matrix equations. In addition, the parametric analysis provides an efficient method to obtain wide low-frequency range band-gaps. Accuracy of the proposed wave-based vibration analysis approach is demonstrated by the simulated and measured results of two sets of beam-like resonator samples.


2021 ◽  
Vol 304 ◽  
pp. 02012
Author(s):  
Le Van Quynh ◽  
Dang Viet Ha ◽  
Bui Van Cuong ◽  
Le Anh Vu ◽  
Tran Van Thoan

Improving ride comfort of earth-moving machinery is important to avoid potential health hazards for machine operator. A vehicle - road coupled interaction model including vehicle body, cab body and driver seat masses is set up under the random excitation of ground surface and a Fuzzy –PID controller is designed for control of the damping coefficient of a semi-active hydraulic cab isolation system (SHCIs) for an earth-moving machinery. The ride performance of SHCIs with a combined controller is evaluated under different movement conditions. The comparison results indicate that the proposed controller for semi-active cab hydraulic isolation system has the significantly improved vehicle ride comfort in compared with passive hydraulic cab isolation system (PHCIs) under large amplitude and low frequency excitations of ground surface.


2018 ◽  
Vol 37 (4) ◽  
pp. 1164-1175 ◽  
Author(s):  
Xiling Xie ◽  
Jianchao Diao ◽  
Yinglei Xu ◽  
Zhiyi Zhang

For preventing the fragile optical communication devices from malfunction caused by the low-frequency seismic excitation, a novel three-dimensional hybrid isolation platform is proposed in this paper. To isolate the horizontal and vertical vibrations simultaneously, the platform is designed as a combination of a rolling isolation system and four three-parameter isolators with active damping. By deriving the governing equations of the three-parameter isolators and the profile of the concave rolling surface, the dynamic model of the whole platform is constructed. Numerical results indicate that the isolation platform has an effective suppression of the horizontal and vertical vibrations. To verify the isolation performance of the hybrid isolation platform, an experiment is conducted in the targeting frequency range. Compared to the amplification factor of 6.2 dB of the three-parameter isolator, the test results exhibit that the hybrid isolation shows no amplification effect in the vertical direction, and the root mean square value of acceleration responses can be decreased by more than 65% in the frequency range of 0–32 Hz. In the horizontal direction, the reduction of the root mean square value of acceleration responses is up to 85% in the same frequency range.


2011 ◽  
Vol 141 ◽  
pp. 59-63
Author(s):  
Hui Jie Yu ◽  
Xiao Long Yan

This paper deals with the analysis of a single degree of freedom vibration isolation system with dry friction damper. Based on the analysis of classical vibration isolation transmission ratio, the conditions of free resonance are found. Regard to the character of vibration isolation system on critical frequency of vibration isolation and resonance, the transmission ratio formula of vibration isolation with friction force under full frequency range is educed which provided the rounded theory principle for free resonance vibration isolation. The vibration isolation system is designed which can realize the non-amplification in low frequency range and better vibration isolation effect in high frequency. Lately, the correctness of the principle is verified by the actual experiment.


1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.


2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.


1997 ◽  
Vol 25 (3) ◽  
pp. 187-213 ◽  
Author(s):  
F. Mancosu ◽  
G. Matrascia ◽  
F. Cheli

Abstract A rigid ring model of the tire for the study of in-plane dynamics and a new technique for determining the parameters of the model are presented in this paper. This model can be used for studying the comfort of vehicles, problems of driving, and braking problems in the longitudinal direction. Comparison with finite element models shows that the rigid ring model of the tire is capable of describing the in-plane eigenmode shapes in the frequency range of 0–130 Hz. The well-known “brush model,” integrated into the tire model, is introduced to take into account the slide phenomena in the contact patch. The parameters of the model can be correlated with the physical properties of the tire so that designers can take advantage of such a correlation in the development of new tires in terms of time, cost, and performance. The technique used to determine the parameters of the model for some automobile tires include the direct measurements of some physical properties (mass, moment of inertia, stiffness) and a method of identification applied on the results from a dynamic test. The model is able to predict experimental data in terms of natural frequencies and relative dampings. Results from the application of this technique on two tires are reported.


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