• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.507-510
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• 2005

Brake judder, which occurs when brakes are suddenly applied to a vehicle driving at high speed, affects the driver's safety to a great extent. It also has a low frequency that drivers can easily feel. Among theses presented, none offered studies using modeling of actual brakes in computer simulation in order to recreate the brake judder phenomenon, and most of them directly applied the frequency generated by the judder. To resolve this issue, this study hopes to develop a computer model that can recreate the phenomenon of brake judder. In this paper, in order to examine the vibration problem occurring when brake is applied on the test car, the multibody dynamic analysis program ADAMS was used to develop a computer model that can recreate the actual braking mechanism while breaking away from the existing understanding of brakes. Thus the existence of the brake judder phenomenon due to DTV(Dist Thickness Variation) and wheel rotating speed was examined through the developed model.

• 한국소음진동공학회논문집
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• 제16권12호
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• pp.1244-1251
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• 2006

The objective of this paper is to get excitation forces of the engine at each of the brackets for the prediction of the vehicle interior noise by the powertrain. A powertrain geometry model is produced by CATIA and its FE model is made by MSC/Patran. A vibration mode analysis and a running mode analysis are experimentally implemented. After getting a satisfied MAC value by doing a correlation about a measured mode analysis value and analyzed value through MSC/Nastran software, all components are assembled through MSC/ADAMS software which is a dynamic analysis tool. We can predict the vibration of brackets which is the last points to occur the force of the engine combustion by analyzing the combustion force produced by engine mechanism.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.133-138
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• 2004

Domestic freight car holding amount is possessing much amount than other vehicle model about 14,000. Problem is happening in bogie device of cast steel structure because is structure that there are many wear departments. Therefore, the KNR is restricting running speed of empty car by 70km/h low. In this research, presented speed elevation way as dynamic characteristic analysis result that use ADAMS and confirm running safety by main line test.

• 한국소음진동공학회논문집
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• 제17권10호
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• pp.993-1001
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• 2007

An analysis model has been developed to assess running safety of railway vehicle passing curves. By using ADAMS/Rail, a computer analysis has been conducted by changing various parameters according to the track conditions. Analysis results show as follows: A derailment coefficient of left wheel was increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A unload rate of left wheel was also increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A wear number of left wheel was increased according to increase of cant at all speed, but only at 35 m/s, it was decreased as increase of cant. A friction coefficient of left wheel was Increased according to increase of cant at all speed, but only at 35 m/s. it was decreased as increase of cant.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.197-204
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• 2003

This paper develops a computer model for estimating the handling of a cabover type large-sized truck. The truck is composed of front and rear suspension systems, a frame, a cab, and ten tires. The computer model is developed using ADAMS. A shock absorber, a rubber bush, and a leaf spring aunt a lot on the dynamic characteristic of the vehicle. Their stiffness and damping coefficient are measured and used as input data of the computer model. Leaf springs in the front and rear suspension systems are modeled by dividing them three links and joining them with joints. To improve the reliability of the developed computer model, the frame is considered as a flexible body. Thus, the frame is modeled by finite elements using MSC/PATRAN. A mode analysis is performed with the frame model using MSC/NASTRAN in order to link the frame model to the computer model. To verify the reliability of the developed computer model, a double lane change test is performed with an actual vehicle. In the double lane change, lateral acceleration, yaw rate, and roll angle are measured. Those test results are compared with the simulation results.

• 한국소음진동공학회논문집
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• 제15권10호
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• pp.1202-1210
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• 2005

This paper develops a computer model for estimating the bump characterisitcs of a cat)over type large-sized truck. The truck is composed of front and rear suspension systems, a frame, a cab, and ten tires. The computer model is developed using MSC.ADAMS. A shock absorber, a rubber bush, and a leaf spring affect a lot on the dynamic characteristic of the vehicle. Their stiffness and damping coefficient are measured and used as input data of the computer model. Leaf springs in the front and rear suspension systems are modeled by dividing them three links and joining them with joints. To improve the reliability of the developed computer model, the frame is considered as a flexible body. Thus, the frame is modeled by finite elements using MSC.PATRAN. A mode analysis is performed with the frame model using MSC.NASTRAN in order to link the frame model to the computer model. To verify the reliability of the developed computer model, a double wheel bump test is performed with an actual vehicle. In the double wheel bump, vortical displacement, velocity, acceleration are measured. Those test results are compared with the simulation results.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.51-59
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• 2006

The high potential for injury involved in rollover accidents warrants the development of a system to protect passengers against such events. To effectively implement such a protection system, it is first necessary to determine rollover criteria (i.e., real time states which indicate the occurrence of rollover events). In this paper, several rollover criteria have been developed based on simplified physical models. Such accidents are first classified into two types, untripped and tripped, according to the main cause that initiates the rollover. Characteristics of these rollover situations are identified by applying appropriate principles of dynamics to corresponding simplified physical models. Two main rollover criteria, Rotational Kinetic Energy (RKE) and Initial Kinetic Energy (IKE), are then introduced based on these characteristics. ADAMS/View simulations have been performed to verify the feasibility of the introduced rollover criteria. ADAMS/Car simulations have also been conducted to get more realistic rollover data with a complete vehicle model. Results of these experiments reveal that our established criteria prove useful for predicting whether actual rollover occurs or not.

• 한국철도학회논문집
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• 제10권5호
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• pp.492-498
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• 2007

곡선통과 새마을호 열차의 주행안전성을 평가하기 위하여 다물체동력학 해석모델이 사용된다. 이 모델과 ADAMS/Rail 사용하여 탈선계수와 관련된 변수의 변화에 따른 민감도해석이 수행된다. 저속에서 우측차륜의 탈선계수와 윤중감소율이 좌측차륜보다 높으나, 고속의 경우는 좌측차륜이 우측차륜보다 높다. 곡선반경의 감소에 따라 탈선계수와 윤중감소율이 감소된다. 완화곡선의 길이가 증가하면 탈선계수는 증가하나 윤중감소율은 변화가 없다. 캔트가 증가하면 탈선계수와 윤중감소율이 증가한다.

• 한국기계기술학회지
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• 제20권6호
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• pp.947-956
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• 2018

This research has been conducted to design upright parts of hand-made vehicles with the purpose of reducing material and machining cost while ensuring structural safety. Aluminum knuckles were modelled with three parts in order to enhance design flexibility as well as to reduce CNC machining cost. A vehicle model was constructed in CAD program and simulated in ADAMS View in order to estimate joint forces developing during 20 degree step steering condition at 60km/h. The joint forces obtained in the vehicle dynamics simulation were used for the structural analysis in ANSYS and dimensions of knuckle parts were adjusted until the lowest safety factor reached 2.0. The weight of knuckle decreased by 50% compared to the previous version that was designed without the structural analysis. The overall manufacturing cost decreased by 33% due to the reduction in the material as well as the CNC machining effort.

• 한국융합학회논문지
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• 제13권4호
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• pp.307-313
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• 2022

차량 실내소음이 엔진의 고출력화와 경량화로 인해 더욱 심각해져 엔진진동의 저감의 중요성이 높아지고 있다. 최근 엔진진동 저감의 대표적인 방법으로 밸런스샤프트 부착이 제시되고 있다. 밸런스샤프트는 피스톤과 콘로드 등의 왕복운동에서 발생하는 진동을 임의의 편심질량을 이용하여 상쇄시키는 장치이다. 따라서 밸런스샤프트는 연비향상 및 차량의 승차감을 동시에 향상시킬 수 있다. 본 논문은 엔진구조로 인해 발생하는 관성력을 유도하고 이를 상쇄하기 위한 밸런스샤프트의 불평형량과 형상을 제시한다. 제시된 두가지 형상의 밸런스샤프트를 ADAMS 다물체동역학 모델로 구현하고, 이를 동역학 시뮬레이션을 통해 실제 거동상태에서의 관성력의 저감을 확인하였다.