• 동력기계공학회지
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• 제12권2호
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• pp.23-28
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• 2008

The primary objective of this study is to truly understand reaction force be due to engine exciting force. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand reaction force was applied MSC.Nastran software. Analyzed frequency response analysis of powertrain mount system. First, engine exciting force was applied field function. Also nonlinear characteristics was applied field function : such as dynamic spring constant and loss factor. And nonlinear characteristics was applied CBUSH. Generally characteristics of rubber mount is constant frequency. But characteristics of hydraulic mount depend to frequency. Therefore nonlinear characteristics was applied. Powertrain mounting system be influenced by powertrain specification, mount position, mount angle and mount characteristics etc. In this study, we was analyzed effects of powertrain mounting system. And we was varied dynamics spring constant and loss factor of mounts.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.967-976
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• 2012

본 논문은 자동차 환경규제에 따른 CO2 감소 및 연비향상을 위하여 Stop&Go 기능을 적용한 소형 승용차에 대한 파워트레인 마운트 (Powertrain Mount) 의 진동 소음 최적화 방향을 제시하였다. 이를 위해 현재 "A" 차량에 적용중인 파워트레인 마운트 시스템을 분석한 후 다구찌 기법을 활용하여 파워트레인 마운트에 적용된 고무 동특성에 대한 다양한 변수를 제시하였고, 고무의 동특성 변수에 의해 만들어진 테스트 제품을 AHP(Analytic Hierarchy Process)기법을 적용하여 Stop&Go 기능에 적합한 진동 소음의 최적화 정도를 검증하였다. 이와 같은 시스템을 파워트레인 마운트의 초기 디자인 검증에 적용함으로써, 파워트레인 마운트의 고무 동특성에 대한 엔지니어링 노하우 (Engineering Know-How) 없이도 엔진의 움직임으로 야기되는 진동 소음의 문제점을 파악하고 이를 효과적으로 제어하는데 큰 역할을 할 것으로 예상된다.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.209-217
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• 2002

This gaper discusses a multidisciplinary design optimization of the engine mounting system to improve the ride quality of a vehicle and to remove the possibility of the resonance between the powertrain system and vehicle systems. The driveline model attempts to support engine mount development by providing sufficient detail for design modification assessment in a modeling environment. Design variables used in this study are the locations, the angles and the stiffness of an engine mount system. The goal of the optimization is both decoupling the roll mode ova powertrain and minimizing the vibration transmitted to the vehicle including the powertrain, simultaneously. By applying forced vibration analysis for vehicle systems and mode decouple analysis for the engine mount system, it is shown that improved optimization result is obtained.

• International Journal of Automotive Technology
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• 제8권6호
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• pp.731-744
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• 2007

A method for dynamic analysis and design calculation of a Powertrain Mounting System(PMS) including Hydraulic Engine Mounts(HEM) is developed with the aim of controlling powertrain motion and reducing low-frequency vibration in pitch and bounce modes. Here the pitch mode of the powertrain is defined as the mode rotating around the crankshaft of an engine for a transversely mounted powertrain. The powertrain is modeled as a rigid body connected to rigid ground by rubber mounts and/or HEMs. A mount is simplified as a three-dimensional spring with damping elements in its Local Coordinate System(LCS). The relation between force and displacement of each mount in its LCS is usually nonlinear and is simplified as piecewise linear in five ranges in this paper. An equation for estimating displacements of the powertrain center of gravity(C.G.) under static or quasi-static load is developed using Newton's second law, and an iterative algorithm is presented to calculate the displacements. Also an equation for analyzing the dynamic response of the powertrain under ground and engine shake excitations is derived using Newton's second law. Formulae for calculating reaction forces and displacements at each mount are presented. A generic PMS with four rubber mounts or two rubber mounts and two HEMs are used to validate the dynamic analysis and design calculation methods. Calculated displacements of the powertrain C.G. under static or quasi-static loads show that a powertrain motion can meet the displacement limits by properly selecting the stiffness and coordinates of the tuning points of each mount in its LCS using the calculation methods developed in this paper. Simulation results of the dynamic responses of a powertrain C.G. and the reaction forces at mounts demonstrate that resonance peaks can be reduced effectively with HEMs designed on the basis of the proposed methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.361-368
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• 2001

This paper introduces optimization techniques to design engine mount properties for passenger vehicle. The design targets are divided into three cases such as optimal positioning of powertrain modes, minimizing vibration of deriver's seat in idling and driving conditions. The proper models, mechanisms of vibration, and characteristics of optimization problems are discussed.

• 한국자동차공학회논문집
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• 제12권2호
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• pp.148-159
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• 2004

This paper discusses vibration mode of the drivesystem considered the vehicle body's dynamic characteristics to study the influence of the vehicle body's dynamic characteristics on the vibration mode of the engine mount system and the ride quality of a vehicle. The simulation model consists of the engine mount system, the powertrain and the rigid or elastic vehicle body. Variables used in this study are the stiffnesses of an engine mount system and the excitation forces. The Goals of the study are analyzing both the vibration transmitted to the vehicle body including the drivesystem and the influence of the vehicle body's dynamic characteristics on the engine mount system. The mode of drivesystems with a rigid and a elastic vehicle body was compared. From the result of the forced vibration analysis for the drivesystem with a elastic vehicle body, it is shown that the vehicle body's dynamic characteristics influence on the engine mount system reciprocally.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.514-519
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• 2011

Recently, the interest in technologies for a highly efficient powertrain, i.e. a variable displacement engine or a light weight car body, to improve the fuel efficiency of automobile saving the environment has been increased. However this trend deteriorates NVH performance of a vehicle and the use of a conventional engine mounting system becomes unsatisfactory. In order to solve this dilemma, an active engine mounting system that could isolate or cancel out vibrations occurred at the powertrain was suggested. In this paper, In order to optimize the electromagnetic active engine mount performance, the actuator of the engine mount through FEM analysis and optimal design, noise and elastomer testing of the prototype through the optimal design of actuators for the electromagnetic active engine mount on the impact of the performance improvement is verified.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1907-1911
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• 2000

In this paper, classical vibration theories are summarized to design engine mount system of passenger vehicles. The vibrational characteristics of powertrain system and its equation of motion are introduced. Based upon the equation, the concept of the center of gravity, the principle inertia axis, the elastic center, and the elastic axis are defined and some new concepts are suggested. The theory of mode decoupling and the relationship between TRA (Torque Roll Axis) and roll mode are also reexamined to support the design concept of engine mount systems.

• 한국정밀공학회지
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• 제25권12호
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• pp.117-124
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• 2008

In early design stage, the simulation of interior noise is useful for the enhancement of the noise, vibration and harshness (NVH) performance in a vehicle. The traditional transfer path analysis (TPA) technology cannot simulate the interior noise since it uses the experimental method. In order to solve this problem, in this paper, the hybrid TPA is developed as the novel approach. The hybrid TPA uses the simulated excitation force as the input force, which excites the flexible body of a car at the mount point, while the traditional TPA uses the measured force. This simulated force is obtained by numerical analysis for the FE (finite element) model of a powertrain. The interior noise is predicted by multiplying the simulated force by the vibro-acoustic transfer function (VATF) of the vehicle. The VATF is the acoustic response in the compartment of a car to the input force at the mount point of the powertrain in the flexible car body. The trend of the predicted interior noise based on the hybrid TPA very well corresponds to the measured interior noise, although there is some difference due to not only the experimental error and the simulation error but also the effect of the air-borne path.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.609-615
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• 2001

In this paper, the eigenvalue sensitivity of vehicle powertrain was investigated by analytic method. The powertrain system was considered as a rigid body with multiple engine mounts, and the engine mounts were supposed as three linear springs in three orthogonal directions. The design parameters for the sensitivity analysis were engine mount properties (positions, stiffness, and orientations) and powertrain properties (mass, second moment of inertia, and center of gravity). Firstly, an effective form of eigenvalue problem for the powertrain system was introduced. Then, the analytic sensitivity of eigenvalue was derived using the equation. Lastly, the derived sensitivity equation was applied to a real powertrain system to provide its correctness and applicability.