• 한국자동차공학회논문집
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• 제13권1호
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• pp.99-108
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• 2005

This paper represents an efficient modeling method of a suspension system for the vehicle dynamic simulation. The suspension links are modeled as composite joints. The motion of wheel is defined as relative one degree of freedom motion with respect to car body. The unique relative kinematic constraint formulation between the car body and wheel enables to derive equations of motion in terms of wheel vertical motion. Thus, vehicle model has ten degrees of freedom. By using velocity transformation method, the equations of motion of the vehicle is systematically derived without kinematic constraints. Various vehicle simulation such as J-turn, slowly increasing steer, sinusoidal sweep steer and bump run has been performed to verify the validity of the suggested vehicle model.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.154-161
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• 1997

This paper presents the method to eliminate the constraint reaction in the Lagrange multiplier form equation of motion by using a generalized coordinate driveder from the velocity constraint equation. This method introduces a matrix method by considering the m dimensional space spanned by the rows of the constraint jacobian matrix. The orthogonal vectors defining the constraint manifold are projected to null vectors by the tangential vectors defined on the constraint manifold. Therefore the orthogonal projection matrix is defined by the tangential vectors. For correcting the generalized position coordinate, the optimization problem is formulated. And this correction process is analyzed by the quasi Newton method. Finally this method is verified through 3 dimensional vehicle model.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.86-94
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• 1995

For a driving vehicle, a self-excited vibration of a pair of steerable wheels about their steering axis accompanied by tramp is called shimmy. Shimmy is caused by the coupling effects of the complicated actions of wheel and tire and the tramp motion of front wheel axle. Because front axle is no longer used on passenger cars shimmy occurring is not considerable. But in commercial vehicles using front wheel axle suspension system shimmy should be considered in design process. In this paper, the model closed to a practical vehicle was developed to analyze the shimmy of a commercial vehicle, and the effects of various design parameters to shimmy were observed by dynamic simulation with multibody dynamics program, DADS. The validity of developed model and analysis results were verified by practical vehicle experiments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.209-212
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• 2005

The look-ahead preview control with the use of limited bandwidth active suspensions is presented. Both a linearized racked vehicle model and a complex nonlinear model based on a commercial multibody dynamic program are used to verify the performance of preview control. The performance of the preview control system is evaluated on the ride quality which is estimated from the acceleration of the driver position. Due to the practical advantages associated with the use of limited bandwidth active control in comparison with full bandwidth systems, the results are considered important to the future development of active tracked vehicle suspensions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.437-444
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• 1998

In this paper, an efficient and accurate formulation for the transient analysis of constrained multibody systems is presented. The formulation employs Kane's method along with the null space method. Kane's method reduces the dimension of equations of motion by using partial velocity matrix: it can improve the efficiency of the formulation. Furthermore, the formulation partitions the coefficient matrix of linear and nonlinear equations into several sub-matrices using kinematic uncoupling. This can solve the equations more efficiently. The proposed formulation can be used to perform dynamic analysis of systems which can he partitioned into several sub-systems such as train systems. One numerical example is given to demonstrate the efficiency and accuracy of the formulation, and another numerical example is given to show its application to the train systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1607-1613
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• 2008

The present investigate is a base investigate required in development of DMT wagon train. And it deduced that follows by developing trail analysis model about Modalohr wagon train and examining traveling movement specific using analysis model developed. Vibration acceleration of all direction was increased with addition of travel speed and first suspension. But in case of right and left vibration acceleration, that could influenced by nonlinear specific of first suspension. Therefore checking about those is needed. Frequency of $2{\sim}3\;Hz$ and $7{\sim}8\;Hz$ generated in Right and left, up, down vibration of vehicle. And right and left vibration of bogie generated $25{\sim}35\;Hz$ in low speed section and frequency of $40{\sim}50\;Hz$ in high speed section, $25{\sim}35\;Hz$ in low speed section, $10{\sim}15$ or $40{\sim}50\;Hz$ in high speed section.

• 한국정밀공학회지
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• 제14권1호
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• pp.205-213
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• 1997

In this study, dynamic analysis of a passenger car is carried out to analyze ride quality over a random road profile. The front suspension of the car is a MacPherson strut type and the rear suspension is a multi- link type. The following five different models are constructed and compared to see the effects of engine vibration and chassis flexibility in the ride quality. (1) one rigid chassis model, (2) a rigid chassis and rigid engine model, (3) a rigid engine and flexible chassis model with one vibration mode, (4) one flexible chassis model with six engine vibration modes and one chassis vibration mode, (5) one flexible chassis model with seven vibration modes and four static correction modes. The result shows that engine vibration modes and the first bending mode of the chassis are important in the ride quality.

• 대한기계학회논문집A
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• 제37권2호
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• pp.257-263
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• 2013

본 논문에서는 파력에너지를 전기에너지로 변환시키는 파력발전기를 다물체 동역학을 이용하여 모델링 하였으며, 계류시스템이 부유식 파력발전기에 미치는 영향에 대해서 분석하였다. 계류시스템이 파력발전기에 미치는 영향을 줄이기 위한 연구가 많이 이루어지고 있다. 구속방정식과 힘 요소를 이용하여 다물체 시스템을 모델링 하였으며, 3 차원 파랑하중을 적용하여 부유체에 작용하는 파력을 모델링 하였다. 파력발전기의 거동과 발전량을 분석하기 의해 상용 다물체 동역학 해석프로그램인 MSC/ADAMS 를 이용하였다. 계류시스템이 있을 때와 없을 때의 결과를 비교하였고, 특히 극한 파랑하중이 작용했을 때의 시뮬레이션을 통해 파력발전기의 안정성을 평가하였다.

• 대한기계학회논문집A
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• 제40권6호
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• pp.557-563
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• 2016

파력발전시스템의 에너지 흡수 효율은 입사파의 파력과 발전기 구동 동력의 비로 정의된다. 흡수 효율은 파력발전시스템의 동적 거동에 의존하기 때문에 파력발전시스템의 에너지 흡수 효율을 예측하기 위해서 파력발전시스템의 동적 해석이 요구된다. 본 논문에서는 에너지 흡수 효율을 예측하기 위하여 파력발전시스템의 동적 해석을 수행하였다. 파력발전시스템의 동적 해석을 위해서 상용 다물체동역학 해석 프로그램인 RecurDyn을 사용하였고, 부유체에 작용하는 파력을 모델링하기 위해서 Morison equation을 적용하였다. 효율분석 결과 파고가 낮고, 주기가 짧을수록 흡수효율이 높아지는 경향을 보인다.

• 대한기계학회논문집A
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• 제36권6호
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• pp.681-689
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• 2012

본 연구에서는 병렬 연결된 해상 크레인을 이용하여 5,000ton 이상의 기가 블록급 대형 중량물을 인양할 때 해상 크레인과 대형 중량물 사이에 연결된 와이어 로프에 작용하는 장력을 계산하기 위해 다물체계 동역학 시뮬레이션을 수행하였다. 이를 위해, 해상 크레인, 바지선, 대형 중량물은 각각 6 자유도 운동을 하고, 이들 사이에는 서로간의 구속에 의한 연성을 가지도록 모델링 하였다. 또한 해상 크레인 및 바지선에 작용하는 외력으로 유체 정역학 힘과 유체 동역학 힘을 고려하였고, 각각의 물체에 독립적으로 작용한다고 가정하였다. 본 시뮬레이션 결과, 향후 해상크레인을 병렬 연결하여 대형 중량물을 인양하는 공법의 안정성을 확인하고 공학적인 지침을 마련할 수 있는 근간이 될 수 있으리라 예상한다.