• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1487-1490
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• 2003

In this paper, the application of object-oriented Data Model to develop a multibody dynamic system, called O-DYN, is introduced. Mechanical components, such as bodies, joints, forces are modeled as objects which have data and method by using object-oriented modeling methodology. O-DYN, a dynamic analysis system, based on the object-oriented modeling concept is made in C++. One example is analyzed through the O-DYN, It is expected that the analysis program or individual module constructed in this paper would be useful for mechanical engineers in predicting the dynamic responses of multibody systems and developing an analysis program

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.289-292
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• 1994

In this paper, the equations of motion are constructed systematically for multibody systems containing closed kinematic loops. For the displacement analysis of the closed loops, we introduce a new mixed coordinates by adding to the reference coordinates, relative coordinates corresponding to the degrees of freedom of the system. The mixed coordinates makes easy derive the explicit closed form solution. The explicit functional relationship expressed in closed form is of great advantages in system dimension reduction and no need of an iterative scheme for the displacement analysis. This forms of equation are built up in the general purpose computer program for the kinematic and dynamic analysis of multiboty systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.267-274
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• 2002

Using a flexible rotating beam test bed, experimental verification of a flexible multibody dynamic simulations for a rotating beam model has been carried out. The test bed consists of a flexible arm, harmonic driver reducer, AC servo motor and DSP board with PC. The mechanical ports of the test bed has been designed using 3D CAD program. For the simulation model, mass and moment of inertia of each part of the flexible rotating beam test bed are also obtained from 3D CAD model. In the flexible multibody dynamic simulations, the substructuring model has been established to capture nonlinear effects of the flexible rotating beam. Through the experimental verification, substructuring model provides better results than those from the linear model in the high speed rotation.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.185-191
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• 2002

A window-based multibody dynamics program CADyna(Computer Aided Dynamics) is developed and applied for kinematic and dynamic analysis ova steering system. The program is composed oft pre-processor, a main processor, and a post-processor. The pre-processor is developed with Visual C7+ and the post-processor is developed with OpenGL and TeeChart. The main processor generates the equations of motion employing velocity transformation technique. The developed program is customized for the design of an intermediate shaft in a steering system.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.190-197
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• 2000

A graphic vehicle modeling pre-processing program and a visualization post-processing program have been developed for AutoDyn7, which is a special program for vehicle dynamics. The Rapid-App for GUI(Graphic User Interface) builder and the Open Inventor for 3D graphic library have been employed to develop these programs in Silicon Graphics workstation. A Graphic User Interface program integrates vehicle modeling pre-processor, AutoDyn7 analysis processor, and visualization post-processor. In vehicle modeling pre-processor, vehicle hard point data for a suspension model are automatically converted into multibody vehicle system data. An interactive graphics capabilities provides suspension modeling aides to verify user input data interactively. In visualization post-processor, vehicle virtual test simulation results are animated with virtual testing environments.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.243-250
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• 2007

In general the Maglev vehicle is run over the elevated track called guideway. Since the guideway is elevated, the flexibility of the guideway has an effect on the dynamic responses of a vehicle such as its stability and ride quality. To improve the running performance of the Maglev vehicle and design a cost effective guideway using the dynamic analysis, the dynamic analysis of the system requires the coupling model of the Maglev vehicle and guideway. A coupling model based on multibody dynamics is proposed and programmed. With the program, the UTM01, a low speed Maglev vehicle, is analyzed and discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.185-191
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• 2001

In many papers, the powertrain system generally has been madeled as one-dimensional torque model. One-dimensional powertrain model may calculate the torque correctly but it does not consider the non-rotational degrees-of-freedom of the powertrain components and the interaction of these degrees-of-freedom with the vehicle body frame and suspension. To consider the non-rotational degrees of freedom, the differential is modeled as a three-dimensional rigid body in this paper. A constant velocity joint is newly formulated and a relative constraint is also formulated to model the motion transfer due to gear ratio of the differential. Implementing the proposed powertrain system in the multibody model, more detail dynamic responses can be obtained. Obtained outputs such as reaction torques on the constant velocity joint and reaction forces on the rack can be useful data in the design of a powertrain.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.2
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• pp.150-156
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• 2004

In this paper, the dynamic behavior of a very flexible cable due to moving multibody system along its length is presented. The very deformable motion of a cable is presented using absolute nodal coordinate formulation, which is based on the finite element procedures and the general continuum mechanics theory to represent the elastic forces. Formulation for the sliding joint between a very flexible beam and a rigid body is derived. In order to formulate the constraint equations of this joint, a non-generalized coordinate, which has no inertia or forces associated with this coordinate, is used. The modeling of this sliding joint is very important to many mechanical applications such as the ski lifts. cable cars, and pulley systems. A multibody system moves along an elastic cable using this sliding joint. A numerical example is shownusing the developed analysis program for flexible multibody systems that include a large deformable cable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.897-898
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• 2011

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1878-1884
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• 2000

In multibody dynamic analysis, one of the most important problems is to reduce computation times for real time simulation. In this paper, a symbolic computation method is implemented and tested for each dynamic analysis step. Applying symbolic formulations to the vehicle dynamics program AutoDyn7, the effectiveness of the symbolic computation method is verified.