• Proceedings of the KSME Conference
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• 2001.11a
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• pp.99-104
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• 2001

Effect of mean stress on the fatigue life of natural rubber for engine mount was investigated. Fatigue damage parameter based on the maximum Green-Lagrange strain was employed to account for the effect of mean stress. A procedure to predict the fatigue life of rubber components based on the maximum Green-Lagrange strain method was proposed. Nonlinear finite element analysis and fatigue test of jang-gu shape specimen were conducted to predict the fatigue life of engine mount. Predicted fatigue lives have a good agreement with tested lives within a factor of 3.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1877-1882
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• 2000

In this paper, an integrated system for dynamic analysis and optimal design of engine mount systems is presented. The system can simulate static and dynamic behaviors of engine mount systems and optimize design parameters such as mount stiffness, mounting locations with desired design targets of frequency or displacement. A FF-engine with an automatic transmission is used to demonstrate the analysis and optimal design capabilities of the proposed design system.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.36-54
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• 1996

This paper presents a design procedure of engine power system for vehicle. The implementation and operation environment of engine plant is somewhat diversed through the various kind of vehicles. Regarding this point, we adopt a multi-purposed design objective function which can be easily modified to reflect diverse mount design rules which have been recommended and used generally by relating fields. To search the mount parameters which provide the optimal performance, a direct search method based on an orthogonal array is developed and applied. Through several simulated results, the effectiveness of the developed disign tool is investigated and discussed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.80-86
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• 2017

This paper describes switching method of the cross-sectional area of the fluid passage way to improve the performance of a hydraulic engine mount with an inertia track and a decoupler. The mount has nonlinear dynamic characteristics depending on the vibrational frequency and amplitude. For the convenience of analysis, two linear motion equations were derived on the basis of the mechanical model according to the low-and high-frequencies. The properties of the transmissibility and dynamic stiffness derived from the equations were investigated according to switching the cross-sectional area of the inertia track and decoupler. Switching method of the cross-sectional area can be derived from the transmissibility plot. In comparison between transmissibility of passive and switchable mounts with an inertia track and a decoupler, the performance of the switchable mount is improved greatly than the passive mount. The resonant peak is remarkably reduced in the high frequency region.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.3
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• pp.305-315
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• 1986

Redesign of the mounting system to minimize vibration of a variable displacement engine through computer simulation is considered. A three degree of freedom model is established for an in-line four-cylinder automobile engine with a three point mounting system. The engine mount locations and angles, and isolator sizes are chosen as design parameters. Constraints on isolator deformations and design parameters are imposed. The gradient projection method is utilized for optimization. Simulation studies show significant vibration reduction can be obtained especially at idling speed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.282-283
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• 2008

According to the development of vehicle technique, the improved NVH performance is required in the vehicle which have the high effectiveness and the high output of the powertrain. This vehicle has to be adapted to active engine mounting system to reduce the vibration in accordance with various vehicle information. The pneumatic active engine mounting system is consist with engine mount, solenoid valve, air tank and control unit totally. The important technique of this system is to reduce the vibration by the air pressure. This paper contains the development process of the pneumatic active engine mounting system and confirm the performance of this system test and vehicle test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.153-160
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• 2001

A general procedure for the design sensitivity analysis of structural dynamic problems has been presented in frame of the FRF-based substructuring formulation. For a system response function, the proposed method gives a parametric design sensitivity formula in terms of the partial derivatives of the connection element properties and the transfer matrix of the subsystems. The derived design sensitivity formula is applied to an engine mount system. An interior noise problem in the passenger car is analyzed using the FRF-based substructuring method and the proposed formulation is adopted to study the response variations with respect to the dynamic characteristics of the engine mounts and the bushes. To obtain the FRFs, a finite element model is built for the engine mount structures, and test data is used for the trimmed body including cabin cavity. The comparison of sensitivities derived by the proposed method and the finite difference method shows that the proposed method is efficient and accurate. The proposed sensitivity analysis method indicates effectively the most sensitive location to the interior noise among the engine mounts and the bushes.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.6
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• pp.553-562
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• 2013

Vehicle vibrations arise from engine and road surface excitations. The engine mount system of a passenger car sustains the engine weight and insulates the excitation force from the engine system. The dynamic properties of viscoelastic material used for the vehicle engine mounts have large variation due to environmental factors such as environmental temperature and humidity etc. The present study aims to investigate the variability of dynamic characteristics in rubber engine mounts considering both environmental temperature change and material model errors/uncertainty. The engine mounts for a passenger car were modeled using finite element method. Then, the dynamic stiffness variability of the engine mounts were estimated using Monte Carlo simulation method. In order to estimate the variations in the storage and loss moduli of the viscoelastic materials, the material properties of the synthetic rubber were expressed as a fractional-derivative model. Next, in order to simulate the uncertainty propagation of the dynamic stiffness for the engine mounts due to the storage and loss moduli variations, the Monte Carlo simulation was used. The Monte Carlo simulation results showed large variation of the engine-mount stiffness along frequency axis.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.209-217
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• 2013

This paper presents an optimal design of a magnetorheological(MR) fluid-based mount(MR mount) that can be used for to vibration control in diesel engines of ships. In this work, a mount that uses mixed-modes(squeeze mode, flow mode, and shear mode) is proposed and designed. To determine the actuating damping force of the MR mount required for efficient vibration control, the excitation force from a diesel engine is analyzed. In this analysis, a model of a V-type engine is considered. The relationship between the velocity and pressure of gas in terms of the torque acting on the piston is derived. Subsequently, by integrating the field-dependent rheological properties of commercially available MR fluid with the excitation force, the appropriate size of the MR mount is designed. In addition, to achieve the maximum actuating force under geometric constraints, design optimization is undertaken using the ANSYS parametric design language software. Through magnetic density analysis, optimal design parameters such as the bottom gap and radius of coil are determined.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.110-120
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• 2000

In order to improve the vibration characteristics of mid sized passenger car automatic transmission at idle experimental and theoretical studies have been carried out. Idle shake in "D" range occurs by various reasons such as characteristics of body bending resonance between subsystems and engine mounts etc. Using full vehicle finite element analyses and modal tests we introduce the way to reduce the idle shake in the early design stage. It shows that the exciting forces are the 2nd order torque and force of engine. A powertrain system modes in "D" range are entirely effected by the additional boundary conditions of drive line. As a result the frequencies of subsystems are arranged to be lined up at the idle frequency range in order to avoid the resonances with subsystems To reduce the idle shake mounts of radiator are tuned to act as a dynamic damper to 1st bending frequency of the body. In addition a hydraulic mount which is optimized by Phase Shift Method is applied to the rear engine mount.e rear engine mount.