Automotive Vehicle Engine Mounting Systems: A Survey

1999 ◽  
Vol 123 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Yunhe Yu ◽  
Saravanan M. Peelamedu ◽  
Nagi G. Naganathan ◽  
Rao V. Dukkipati
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Frequency Range ◽  
Engine Mounts ◽  
Performance Requirements ◽  
Vehicle Engine ◽  
Engine Mount ◽  
Active Engine ◽  
Stiffness And Damping

This study divided into three portions to provide performance requirements; overview and development of various engine mounts; and the optimization of engine mount systems. The first part provides an insight about the ideal engine mount system that should isolate vibration caused by engine disturbance force in various speed range and prevent engine bounce from shock excitation. This implies that the dynamic stiffness and damping of the engine mount should be frequency and amplitude dependent. Therefore, the development of engine mounting systems has mostly concentrated on improvement of frequency and amplitude dependent properties. The second part starts discussion on the conventional elastomeric mounts that offer a trade-off between static deflection and vibration isolation. The next level, passive hydraulic mounts can provide a better performance than elastomeric mounts especially in the low frequency range. Subsequently, semi-active and active techniques are used to improve performance of hydraulic mounts by making them more tunable. The active engine mounting system can be very stiff at low frequency and be tuned to be very soft at the higher frequency range to isolate the vibration. The final part is about the optimization of engine mounting systems. An overview of the current work on this optimization shows some limitations. Further study is needed to consider the nonlinearities and variations in properties of different types of mounting systems.

Non-Linear Modeling and Parameter Identification of Semi-Active Engine Mounts With Air Spring

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Rong Guo ◽  
Zi-wei Zhou
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Superior Performance ◽  
Test Rig ◽  
Air Spring ◽  
Engine Mounts ◽  
Air Chamber ◽  
Non Linear ◽  
Engine Mount ◽  
Active Engine

Abstract Car manufacturers have been motivated to apply semi-active engine mounts to ensure superior performance in vibration attenuation during idle condition and better ability to isolate vibration which is generated by engine unbalanced force at high frequencies. This paper develops a non-linear lumped parameter model of semi-active engine mounts with air spring that focuses on the non-linearity of the rubber diaphragm and the air chamber. Then, the main rubber dynamic stiffness parameters are identified through experimental approaches with a novel-designed test rig. Other parameters including effective pumping area, main rubber spring bulge stiffness, fluid channel inertia and resistance, rubber diaphragm, and air-chamber parameters are attained through finite element analysis (FEA). Supported by the identified lumped parameters, the non-linear mathematical model could be simulated. In addition, the dynamic characteristics of the semi-active engine mount are tested through the original test rig. Therefore, comparing with the tested dynamic characteristics, the simulation result can validate the developed model and thus facilitate the structure design of the semi-active engine mount.

Developing of an Active Hydraulic Bushing for Multi-Displacement Engines

2006 ◽  
Author(s):  
S. Arzanpour ◽  
M. F. Golnaraghi
Keyword(s):  
Mathematical Model ◽  
Research Effort ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Feedback Signal ◽  
Frequency Range ◽  
Engine Mount ◽  
Isolation Requirements ◽  
Stiffness And Damping ◽  
The Mathematical Model

This paper outlines the development of an active hydraulic bushing system for the Multi Displacement System (MDS) Engine isolation problems. The prior art research effort on engine mounts and bushings has so far focused on the improvement of the mount dynamic stiffness properties. The optimum dynamic stiffness and damping of the engine bushings is both frequency and amplitude dependent. While these systems are available commercially, they have many limitations, particularly for new vehicle models and new engine generations such as MDS engines. A suitable isolator for an MDS engine should be half as stiff in the operating frequency range of the engine (5-70 Hz) in MDS mode, while showing the same performance as conventional hydraulic bushings in normal engine operations. Passive hydraulic bushings are not capable of meeting the isolation requirements discussed for the MDS engines because they are not adjustable. There are different parameters which contribute to the dynamic stiffness response of a hydraulic bushing. Some of those parameters are defined by passive components such as rubber stiffness and damping. However, other parameters such as the pressure inside the bushing can be altered actively. The mathematical model of a conventional hydraulic bushing is given in this paper. The model suggests that the pressure inside the bushing has a significant role in the dynamic stiffness response of the bushing. As a result, an additional pumping chamber is introduced as a solution. The pump is utilized to adjust the pressure inside the bushing based on the engine excitation frequency. This pump can be driven by proper actuators which can produce pressure differences in the frequency range of interest. The mechanical and mathematical model of such a system is derived using a simplified linear model. This technique enables the engine mount to adjust to the dynamic stiffness characteristics by applying a feedback signal to the actuator. The feedback signal to the actuator is also obtained using the mathematical model for many required cases yet adjustable for others. The response of the system is discussed in frequency domains. The simulation results prove that the additional pumping chamber can effectively be used to control the stiffness of the conventional hydraulic bushings.

scholarly journals Dynamic characterization of controlled multi-channel semi-active magnetorheological fluid mount

2021 ◽  
Vol 12 (2) ◽  
pp. 751-764
Author(s):  
Zhihong Lin ◽  
Mingzhong Wu
Keyword(s):  
High Frequency ◽  
Optimization Design ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Vehicle Model ◽  
Mr Fluid ◽  
Unbalanced Force ◽  
Low Frequency Vibration ◽  
Engine Mount

Abstract. In this paper, a novel structure of a controlled multi-channel semi-active magnetorheological (MR) fluid mount is proposed, including four controlled channels and one rate-dip channel. Firstly, the magnetic circuit analysis, rate-dip channel optimization design, and MR fluid mount damping analysis are given. Secondly, the mathematical model of the controlled multi-channel semi-active MR fluid mount is constructed. We analyze the effect of controlled multi-channel closing on the dynamic characteristics of the mounts and the effect of the presence or absence of the rate-dip channel on the low-frequency isolation of the mount. Finally, the controlled multi-channel semi-active MR fluid mount was applied to the 1/4 vehicle model (a model consisting of an engine, a single engine mount, a single suspension and a vehicle frame), with the transmissibility of the engine relative to the vehicle frame at low frequency and the transmissibility of the engine reciprocating unbalanced force to the vehicle frame magnitude at high frequency as the evaluation index. Numerical simulation shows the following points. (1) The controllable multi-channel semi-active MR fluid mount can achieve adjustable dynamic stiffness and damping with applied 2 A current to different channels. (2) With known external excitation source, applied currents to different controllable channels can achieve the minimum transmissibility and meet the mount wide-frequency vibration isolation requirement, while adding a rate-dip channel can improve the low-frequency vibration isolation performance of the MR fluid mount. (3) Switching and closing different controllable channels in the 1/4 vehicle model can achieve the minimum transmissibility of low-frequency engine vibrations relative to the vehicle frame and high-frequency engine vibrations reciprocating an unbalanced force to the vehicle frame. Therefore, the design of the controllable multi-channel semi-active MR fluid mount can meet the wide-frequency isolation.

Dynamic Characteristics Research of Magneto-Rheological Fluid Engine Mount

2015 ◽  
Vol 752-753 ◽  
pp. 913-917
Author(s):  
Gong Yu Pan ◽  
Qian Qian Wang ◽  
Xin Yang
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Simulation Software ◽  
New Type ◽  
Engine Mount ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Vibration Isolation Performance ◽  
Isolation Performance

In order to improve the vibration isolation performance of engine mount, a new type of magneto-rheological semi-active mount with multiple inertia tracks is designed based on the existing magneto-rheological semi-active mount . The mechanical model is established according to the mount. The expression of the dynamic stiffness and damping lag angle is deduced, then the dynamic characteristics is simulated in the simulation software. At the same time, verify this model correct by the experiments.

scholarly journals Optimal fluid passageway design methodology for hydraulic engine mounts considering both low and high frequency performances

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2749-2757
Author(s):  
Yuan Li ◽  
Jason Zheng Jiang ◽  
Simon A Neild
Keyword(s):  
High Frequency ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Relative Displacement ◽  
Wide Frequency Range ◽  
Performance Criteria ◽  
Frequency Model ◽  
Engine Mounts ◽  
Engine Mount ◽  
And Performance

This paper investigates the potential for improving the performance of hydraulic engine mounts through fluid passageway designs. In previous studies, a few simple inertia track designs have been investigated with moderate improvements obtained. However, there are countless alternative design possibilities existing; while analyzing each one of them in turn is impracticable. To this end, this paper introduces a systematic methodology to optimize fluid passageway designs in a hydraulic engine mount. First, beneficial fluid passageway configurations are systematically identified using a linearized low-frequency model that captures the relative displacement transmissibility. A nonlinear model is then used to fine-tune the fluid passageway designs for the low-frequency transmissibility improvement, and also for the assessment of high-frequency dynamic stiffness performance. The obtained beneficial designs present performance advantages over a wide frequency range. The design approach introduced in this study is directly applicable to other engine mount models and performance criteria.

scholarly journals Vibration Control and Design of Vehicle Engine Mount Activated by Magnetorheological Fluid

2011 ◽  
Vol 2-3 ◽  
pp. 1077-1081 ◽  
Author(s):  
Zhao Xue Deng ◽  
Ling Zheng
Keyword(s):  
Fuzzy Logic ◽  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Fuzzy Logic Controllers ◽  
Vehicle Engine ◽  
Engine Mount ◽  
Magneto Rheological ◽  
Logic Controllers

Magneto-rheological (MR) fluid mount demonstrates excellent performance of vibration isolation in a wide frequency range and potential application in engineering. In this paper, a new mixed mode MR mount is proposed and an analytical model is established and used to predict the performance of MR mount. Meantime, a six degrees of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and its state space form is established. LQR and fuzzy-logic controllers are designed and synthesized to actively control the imposed vibration. The simulation results show that the proposed LQR or fuzzy-logic controllers can isolate the vibration of vehicle engine in a wide frequency range. The amplitudes can be suppressed well by employing this mount system. Its effectiveness will be verified via experiment in the second part of this work.

scholarly journals Methods for Measuring the Dynamic Stiffness of Resilient Rail Fastenings for Low Frequency Vibration Isolation of Railways, Their Problems and Possible Solutions

2005 ◽  
Vol 24 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Chris Morison ◽  
Anbin Wang ◽  
Oliver Bewes
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Inertial Force ◽  
Transport Systems ◽  
Frequency Range ◽  
Low Frequency Vibration ◽  
Urban Rail ◽  
Low Stiffness ◽  
European Standards

Low frequency ground or structure-borne sound and vibration emission from urban rail transport systems can be greatly reduced by reducing the stiffness of the rail fastening. Estimates and models of the efficacy of such systems require accurate measurements of their dynamic stiffness over the frequency range of interest, and European Standards make recommendations for such measurements. This paper describes these methods and their shortcomings when applied to modern complete assemblies with low stiffness, one problem of which is the contribution of inertial forces at frequencies approaching and above the natural resonance of the system. This paper suggests a method for correcting for this inertial force, and tests this correction with the driving point method of dynamic stiffness measurement when applied to the Pandrol VANGUARD resilient rail fastening. The preliminary tests effectively triple the frequency range of valid measurements, a result which could be improved when applied to stiffer systems or with further improvements to the test equipment.

Engine Mount Optimization for Vibration Isolation in Motorcycles

2006 ◽  
Author(s):  
Sudhir Kaul ◽  
Anoop K. Dhingra ◽  
Timothy G. Hunter
Keyword(s):  
Optimization Problem ◽  
Vibration Isolation ◽  
Total Force ◽  
Engine Mounts ◽  
The Road ◽  
Design Variables ◽  
Swing Arm ◽  
Engine Mount ◽  
Six Degree Of Freedom

This paper presents a comprehensive model to capture the dynamics of a motorcycle system in order to evaluate the quality of vibration isolation. The two main structural components in the motorcycle assembly - the frame and the swing-arm - are modeled using reduced order finite element models; the power-train assembly is modeled as a six degree-of-freedom (DOF) rigid body connected to the frame through the engine mounts and to the swing-arm through a shaft assembly. The engine mounts are modeled as tri-axial spring-damper systems. Models of the front-end assembly as well as front and rear tires are also included in the overall model. The complete vehicle model is used to solve the engine mount optimization problem so as to minimize the total force transmitted to the frame while meeting packaging and other side constraints. The mount system parameters - stiffness, position and orientation vectors - are used as design variables for the optimization problem. The imposed loads include forces and moments due to engine imbalance as well as loads transmitted due to irregularities in the road surface through the tire patch.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

On the Effects of Mistuning a Force-Excited System Containing a Quasi-Zero-Stiffness Vibration Isolator

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Ali Abolfathi ◽  
M. J. Brennan ◽  
T. P. Waters ◽  
B. Tang
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Vibration Isolator ◽  
Linear Vibration ◽  
Vibration Isolators ◽  
Zero Dynamic ◽  
Low Frequency Vibration ◽  
Excited System ◽  
Better Than

Nonlinear isolators with high-static-low-dynamic-stiffness have received considerable attention in the recent literature due to their performance benefits compared to linear vibration isolators. A quasi-zero-stiffness (QZS) isolator is a particular case of this type of isolator, which has a zero dynamic stiffness at the static equilibrium position. These types of isolators can be used to achieve very low frequency vibration isolation, but a drawback is that they have purely hardening stiffness behavior. If something occurs to destroy the symmetry of the system, for example, by an additional static load being applied to the isolator during operation, or by the incorrect mass being suspended on the isolator, then the isolator behavior will change dramatically. The question is whether this will be detrimental to the performance of the isolator and this is addressed in this paper. The analysis in this paper shows that although the asymmetry will degrade the performance of the isolator compared to the perfectly tuned case, it will still perform better than the corresponding linear isolator provided that the amplitude of excitation is not too large.

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