유한 요소 해석 기법을 이용한 고속 철도 차량의 집전 성능 해석

정성필(Sung Pil Jung),박태원(Tae Won Park),김영국(Young Guk Kim),박찬경(Chan Kyoung Park),백진성(Jin Sung Paik) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.7

본 논문에서는 상용 유한 요소 해석 프로그램인 SAMCEF 를 이용하여 고속 철도 차량의 집전성능을 예측할 수 있는 해석 모델을 개발하였다. 3 자유도 스프링-댐퍼-질량의 판토그래프 모델을 생성하였고, 실제 시스템과의 리셉턴스를 비교함으로써 신뢰성을 검증하였다. UIC 799 OR 기준에서 제시한 가선계의 이론적 파동전파 속도와 가선계 유한 요소 해석 모델에서 측정한 파동 전파 속도를 비교 하였다. 드로퍼의 길이를 조절하여 전차선의 중력에 의한 초기 처짐 현상을 구현하였다. 가선계와 판토그래프를 접촉 요소를 이용하여 연성하였으며, 판토그래프가 300 ㎞/h 및 370 ㎞/h 로 주행할 때의 접촉력 변화를 도출하였다. 접촉력의 평균, 표준편차, 최대 및 최소값 등을 분석함으로써 본 논문에서 제시한 해석모델의 유효성을 검증하였다. In this study, a simulation model to estimate the current-collection performance of a high-speed train was developed by using a commercial finite element analysis software, SAMCEF. A three-dimensional springDdamperDmass model of a pantograph was created, and its reliability was validated by comparing the receptance of the model to that of the actual pantograph. The wave propagation speed of the catenary model was compared with the analytical wave propagation speed of the catenary system presented in the UIC 799 OR standard. The length of the droppers was controlled, and the pre-sag of the contact wire due to gravity was considered. The catenary and the pantograph were connected by using a contact element, and the contact force variation when the pantograph was moved at velocities of 300 ㎞/h and 370 ㎞/h was obtained. The average, standard deviation, maximum, and minimum values of the contact force were analyzed, and the effectiveness of the developed simulation model was examined.

자동차 와이퍼 시스템의 유연 다물체 동역학 해석

정성필(Sung Pil Jung),박태원(Tae Won Park),정원선(Won Sun Cheong) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.2

본 논문에서는 플랫 타입 블레이드를 장착한 와이퍼 시스템의 성능을 예측하기 위한 동역학 해석방법을 제시하였다. 고무 재질로 이루어진 블레이드는 비선형의 특성을 갖기 때문에, 블레이드의 동적 특성을 나타내기 위하여 모달 좌표계와 절대 절점 좌표계를 이용하였다. 블레이드 단면의 굽힘 특성을 파악하기 위해 블레이드에 대한 구조 해석을 실시하였다. 해석 결과에 따라 블레이드 단면을 강체, 유연체 및 대변형체의 3 부분으로 구분하였다. 모달 좌표계와 절대 절점 좌표계를 이용하여 블레이드 단면의 유연체 및 대변형체를 표현하였다. 동역학 해석 결과를 검증하기 위해 실험을 실시하였고, 결과비교를 통해 본 연구에서 생성한 블레이드에 대한 유연 다물체 모델의 신뢰성을 검증하였다. This paper presents the dynamic analysis method for estimating the performance of flat-type blades in wiper systems. The blade has nonlinear characteristics since the rubber is a hyper-elastic material. Thus, modal coordinate and absolute nodal coordinate formulations were used to describe the dynamic characteristic of the blade. The blade was structurally analyzed to find the bending characteristics of the cross section of the blade. According to the analysis results, the blade section is divided into three deformation bodies: rigid, small, and large. For the small deformation body, the modal coordinate formulation is used, while the absolute nodal coordinate formulation is used for the large deformation body. To verify the dynamic analysis result, an experiment was performed. The simulation and experiment results were compared to verify the flexible multi-body dynamic model.

기어 치형 설계 프로그램 개발에 관한 연구

정성필(Sung Pil Jung),박태원(Tae Won Park) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.8

In this paper, the gear design program is presented. The profile of gears is created using classical mathematic formulations. In each gear, a kinematic joint is applied and one can define the 2D contact condition between gear pairs. Initial and boundary conditions such as force, torque, velocity, acceleration, etc. can be set. Thus, it is possible to analyze dynamic characteristics of gear pairs such as reaction moment and the variation of angular velocity. In order to find the optimal profile of gear pairs, two optimization methods based on design of experiments are inserted in the program; One is the Taguchi method and the other is the response surface analysis method. To verify the program, the rack & pinion gear is created and analyzed. Simulation results show that the developed program is useful and result data is reliable.

MATLAB 을 이용한 유연 다물체 시스템의 해석 및 제어

정성필(Sung Pil Jung),박태원(Tae Won Park) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.5

In this paper, analysis and control of the flexible multibody system using MATLAB is presented. The equations of motion of a flexible body are derived in terms of the modal coordinate. The rigid-flexible multibody dynamic solver is developed. Finite element information required to analyze motion of flexible bodies is imported from ANSYS. The modified finite element data, such as modal mass matrix, modal stiffness matrix and constraint mode shapes, is calculated in the solver. Since the solver is developed using MATLAB, it is very easy to connect with SIMULINK which is widely used to control motion of the multibody system. Several simulations are implemented to verify the developed solver. A control example is carried out and the usefulness of the developed solver is demonstrated.

자동차용 디스크 브레이크의 열간 저더 현상에 대한 연구

정성필(Sung Pil Jung),박태원(Tae Won Park),심경석(Kyeong Suk Sim),이진희(Jin Hee Lee),김욱현(Wook Hyun Kim) 한국소음진동공학회 2011 한국소음진동공학회 학술대회논문집 Vol.2011 No.4

자동차용 디스크 브레이크의 Hot judder 해석

정성필(Sung Pil Jung),박태원(Tae Won Park),조재익(Jae Ik Cho),정기범(Gi Beom Jeong),정원선(Won Sun Chung) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

In this study, a transient FE analysis method was used to analyze the fully coupled thermo-mechanical problem for a disc brake system. Mechanical and thermal model for the disc brake were generated separately, and solved iteratively. Three dimensional FE model of a disc brake was created. The mechanical model of the disc brake was assumed to be in braking with an acceleration of 0.3g from 1400 rpm to 700 rpm. The thermal model with an initial temperature of 80℃ interacts with the mechanical model, and the friction heat between the pad and disc is generated by the friction contact condition. Due to the heat generation, the material of disc is expanded and alters the contact condition.

자동차용 휠의 내구성능 예측을 위한 복합축 응력해석 및 실험적 검증

정성필(Jung, Sung-Pil),정원선(Chung, Won-Sun),박태원(Park, Tae-Won) 한국소음진동공학회 2011 한국소음진동공학회 논문집 Vol.21 No.10

In this paper, the finite element analysis model of the mult-axial wheel durability test configuration is created using SAMCEF. Mooney-Rivlin 2nd model is applied to the tire model, and the variation of the air pressure inside the tire is considered. Vertical load, lateral load and camber angle are applied to the simulation model. The tire rotates because of the friction contact with a drum, and reaches its maximum speed of 60 km/h. The dynamics stress results of the simulation and experiment are compared, and the reliability of the simulation model is verified.

고속 철도 차량용 판토그래프와 가선계의 접촉력 예측을 위한 수치 해석 모델 개발

정성필(Jung, Sung-Pil),박태원(Park, Tae-Won),김영국(Kim, Young-Guk),백진성(Paik, Jin-Sung) 한국소음진동공학회 2011 한국소음진동공학회 논문집 Vol.21 No.5

This study aims to create a numerical analysis model which can investigate the dynamic interaction between pantograph and overhead contact wire used for a high-speed railway vehicle, and validate the simulation results according to EN 50318 standard. Finite element analysis models of pantograph and overhead contact line are created using SAMCEF, a commercial FE analysis program. The mean, standard deviation, maximum and minimum values of contact forces are obtained. The simulation results are validated according to EN 50318, and the possibility of simulating the collecting characteristic of an actual pantograph system by using the developed model is discussed.

자동차용 프리텐셔너의 성능향상을 위한 실험적 연구

정성필(Sung Pil Jung),박태원(Tae Won Park),송택림(Taeck Rim Song) 한국자동차공학회 2010 한국 자동차공학회논문집 Vol.18 No.2

This study presents the practical design modification to improve the retracting performance of the pyro-typed high power pretensioner. 3 components of the pretensioner are redesigned and the usefulness of the design modification is verified by the experiment. During the pretensioning process, the gas blast generated from the gunpowder is transferred to the rack-pinion gear through the manifold. The rack-pinion gear is connected with the spool where the webbing is rolled up. According to the rotation of the pinion, the spool is turned and the webbing is winded. To help the gas blast flow well, the shape of the inner cross section of the manifold is changed. The spur gear design program is developed and used to find the best combination of the rack-pinion gear pair to increase the power transmission efficiency. The pinion guide is installed on the spool to prevent the vibration of the pinion. As a result of the experiment, the amount of the web retraction length is increased when every single design modification is applied. Therefore, the retracting performance of the pretensioner is considered to be improved if the presented design modifications are applied.

유한 요소법을 이용한 자동차용 디스크 브레이크의 열간 저더 해석

정성필(Sung Pil Jung),박태원(Tae Won Park),정원선(Won Sun Chung) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.4

차량 제동시 디스크와 패드사이의 미끄럼 접촉에 의해 발생하는 마찰열은 재질의 열 탄성 변형을 일으키고, 이는 접촉면의 압력 분포에 영향을 끼친다. 이러한 열탄성 불안정성 (Thermo-Elastic Instability, TEI)은 디스크의 고유 진동모드와 결합되어 열섬 현상 및 열간 저더 진동을 발생시킨다. 본 연구에서는 상용 유한 요소 해석 프로그램인 SAMCEF 를 이용하여 자동차용 통풍식 디스크에 대한 3 차원 열간 저더 해석을 수행하였다. Staggered approach 에 의거한 중간 처리기를 이용하여 구조-동역학 해석 결과와 열 전달 해석 결과를 교환하였다. 디스크 표면에 열섬이 발생하는 것을 확인하였고, 이를 디스크 고유 진동 모드와 비교함으로써 모드 형상과 열섬 분포의 관계를 분석하였다. Thermal energy generated because of the friction between the disc and pad is transferred to both sides and causes thermal expansion of the material, which affects the contact pressure distribution. This phenomenon, which is called thermoelastic instability (TEI), is affected by the natural mode of a disc. TEI results in the formation of a hot spot and causes hot judder vibrations. In this study, three-dimensional analysis of the hot judder of a ventilated disc for automotives was performed by using the commercial finite element analysis program, SAMCEF. The intermediate processor based on a staggered approach was used to exchange the result data of the mechanical and thermal model. The hot spot was formed on the surface of the disc, and the number of hot spots was compared with the natural mode of the disc.