• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.299-310
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• 2017

In this work, an independent-load friction wedge model was developed using the ADAMS/View program to predict the performance of a freight vehicle with a bogie employing a 3-piece friction wedge. The friction wedge model can generate friction according to lateral and vertical directions of the bolster. The developed friction wedge model was applied to the ADAMS/Rail vehicle model, and results of the dynamic analysis showed a critical speed of 210km/h. In the linear safety analysis, it was confirmed that the lateral and vertical limit of acceleration of the vehicle were satisfied based on UIC518. In the 300R curve line, the application speed was 70km/h, which was satisfied with the limit acceleration of the car-body and bogie based on UIC518. Also, the developed model satisfied the wheel loading, lateral force and derailment coefficient of "The Regulations on Safety Standards for Railway Vehicles"

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4142-4148
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• 2013

Because of effective fruit growing and management in the slope land, the use of orchard vehicle with lifting utilities has been increased. For this reason the study on the stability of that vehicle for worker's safety is needed. This study is investigated on the stability estimation of orchard vehicle with four wheels and dual rectangular-type lifting utilities which can be moved on the dirt sloping load. Through the multi-body dynamics analysis on the vehicle mechanism, overturning angles of 19.2 and $34.6^{\circ}$ in the right-left and front-rear direction can be calculated. It is determined tractive resistances and required powers of the wheels. And through the finite element analysis on the frame of lifting utility its maximum von-Mises stress is 146 MPa and it is structural stable. Therefore it is known that the orchard vehicle with wheels and lifting utilities has static and dynamic stability.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.5
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• pp.359-371
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• 2013

This paper is the first paper among two papers which constitute the paper about the rigid body dynamic analysis on the spent nuclear disposal canister under accidental drop and impact on to the ground. This paper performed the general theoretical study on the rigid body dynamic analysis. Through this study the impulsive force which is occurring in the spent nuclear fuel disposal canister under accidental drop and impact to the ground and required for the structural safety design of the canister is intended to be theoretically formulated. The main content of the theoretical study is about the equation of motion in the multibody dynamics. On the basis of this study the impulsive force which is occurring in the multibody in the case of collision between multibody is theoretically formulated. The application of this theoretically formulated impulsive force to computing the impulsive force occurring in the spent nuclear fuel disposal canister under accidental drop and impact to the ground is investigated.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.859-864
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• 2009

When the vehicle passes through turnout, the design is required to minimize the change of lateral force. Therefore, in case the vehicle passed the through turnout, we ought to execute dynamic analysis of the interaction between the vehicle and turnout in order to make an estimate of the lateral force and the derailment coefficient on the turnout. In this paper, we established the analytical model of the vehicle and turnout and analysed running safety when the vehicle passes through turnout in order to improve running safety of the vehicle on turnout. Also, to verify the vehicle and turnout model, we analysed reaction force and running behavior between wheel and rail, and running safety of the vehicle by changing cradle part and the tongue rail when the vehicle passes through turnout.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.157-165
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• 2016

In wartime conditionsmilitary combat vehicles are required to be driven on rough roads that have significant obstacles. A wheel type dog-horse robot with a rotary suspension system was applied to overcome the obstacles. To achieve real-time analysis, a simplified model was proposed by using velocity transformations. Through comparison with the multi-body dynamics model, the efficiency and accuracy of the proposed modeling was proven.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.10
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• pp.1039-1044
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• 2015

During the development of vehicles, durability tests are time consuming and costly. Recently, automobile companies have attempted to develop their own durability evaluation procedures by modifying and complementing . In this paper, we propose an integrated computer-aided engineering (CAE) method to evaluate the durability of a torsion beam axle (TBA). We compare this method with the standardized durability evaluation method used by an actual automobile company in order to determine the feasibility of this method. We compare the results with the test result data to enable us to estimate the reliability of the analysis results. In this study, we analyze the processes and results of the quasi-static fatigue analysis, and found improved methods and problems. Furthermore, we perform a thorough test using the requirements of the actual company. Based on the results, the structural analysis process in the quasi-static fatigue analysis method was superseded by the multi-body dynamics analysis process. Generally, this method is referred to as the resonance-fatigue analysis method.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.122-130
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• 2013

Rail geometries such as cant, grade and curvature can be easily represented by means of a track coordinate system. In this analysis, in order to derive a dynamic and constraint equation of a wheelset, the track coordinate system is used as an intermediate stage. Dynamic and constraint equations of railway vehicle bodies except the wheelset are written in the Cartesian coordinate system as a conventional method. Therefore, whole dynamic equations of a railway vehicle are derived by combining wheelset dynamic equations and dynamic equations of railway vehicle bodies. Constraint equations and constraint Jacobians are newly derived for the track coordinate system. A process for numerical analysis is suggested for the derived dynamic and constraint equations of a railway vehicle. The proposed dynamic analysis of a railway vehicle is validated by comparison against results obtained from VI-RAIL analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.409-414
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• 2007

Nowadays, with the advancement of computational mechanics, and vehicle dynamics simulation linked up with virtual testing laboratory(VTL) and virtual proving ground(VPG) technologies has become a useful method for analyzing numerous driving performances and diverse noise/vibration characteristics. In this paper, the analytical vehicle model based on multi-body dynamics theory was developed to investigate the vibration characteristics according to various road conditions. For the purpose, the whole vehicle parameters, each vehicle's part parameter, and part connecting elements such as spring, damper, and bush were measured by an experiment. Also, the vehicle dynamics model, which includes the front suspension, rear suspension, steering, front wheel, rear wheel, and body subsystems has been constructed for computer simulation. With the developed vehicle dynamics model, three forces and three moments measured at each wheel center were applied to evaluate and analyze dynamics and vibration characteristics for miscellaneous road conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.486-494
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• 2001

This paper presents a real-time multibody vehicle dynamic analysis method using recursive Kanes formulation and suspension composite joints. To shorten the computation time of simulation, relative coordinate system is used and the equations of motion are derived using recursive Kanes formulation. Typical suspension systems of vehicles such as MacPherson strut suspension system is modeled by suspension composite joints. The joints are derived and utilized to reduce the computation time of simulation without any degradation of kinematical accuracy of the suspension systems. Using the develop program, a multibody vehicle dynamic model is formed and simulations are performed. Accuracy of the simulation results is compared to the real vehicle field test results. It is found that the simulation results using the proposed method are very accurate and real-time simulation is achieved on a computer with single PowerPC 604 processor.

• Journal of KSNVE
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• v.9 no.6
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• pp.1259-1266
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• 1999

The objective of this investigation is to develop a compliant track link model and apply this model to the multi-body dynamic analysis of high mobility tracked vehicles. Two major difficulties encountered in developing the compliant track models. The first one is that the integration step size must be kept small in order to maintain the numerical stability of the solution. This solution deals with high oscillatory signals resulting from the impulsive contact forces and stiff compliant elements to represent the joints between the track links. The second difficulty is due to the large number of the system equations of motion of the three dimensional multibody tracked vehicle model. This problem was sloved by decoupling the equations of motion of the chassis subsystem and the track subsystems. Recursive methods are used to obtain a minimum set of equations for the chassis subsystem. Several simulation scenarios were tested for the high mobility tracked vehicle including accelaeration, high speed cruising, braking, and turning motion in order to demonstrate the effectiveness and validity of the methods proposed in this investigation.