• 한국정밀공학회지
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• 제27권4호
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• pp.46-52
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• 2010

A flexible-rigid multibody analysis was pen armed to examine the dynamic response of a heavy handling robot system under a worst motion scenario. A rigid body dynamics analysis was solved and compared with flexible-rigid multibody analysis. The modal analysis and test were also carried out to establish the accuracy and the validation of the finite element model used in this paper. For the flexible-rigid multibody simulation, stresses in several major bodies were interested, so that those parts are flexible and other parts are modeled as rigid body in order to reduce computer resources.

• 대한기계학회논문집
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• 제17권10호
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• pp.2483-2490
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• 1993

This paper presents a systematic formulation for the kinematic and dynamic analysis of flexible multibody systems. The system equations of motion are derived in terms of relative and elastic coordinates using velocity transformation technique. The position transformation equations that relate the relative and elastic coordinates to the Cartesian coordinates for the two contiguous flexible bodies are derived. The velocity transformation matrix is derived systematically corresponding to the type of kinematic joints connecting the bodies and system path matrix. This matrix is employed to represent the equations of motion in relative coordinate space. Two examples are taken to test the method developed here.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.584-589
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• 2001

The latch needle cam system of circular knitting machines is analysed using multibody dynamics. A formulation is made to obtain the vertical stiffness between the needle and the cam. By implementing this formulation into data of the multibody dynamics program, the motion and the force between the needle and the cam are obtained.

• 한국정밀공학회지
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• 제20권6호
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• pp.160-166
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• 2003

Interest in advanced vehicles results in correspondingly increased interest in modeling and simulation of the dynamic behavior of Maglev-type vehicle systems. DADS is a program especially suited for the analysis of multibody mechanical systems. This paper demonstrates the application of DADS to the dynamic modeling and simulation of such advanced vehicles. A brief description is made of the modeling requirements of magnetically levitated systems, along with a summary of some of the related capabilities of DADS. As a case study, an analysis of a vehicle based on the UTM01 system is presented. This paper shows that the presented modeling technique is applicable to the dynamic characteristics evaluation and control law design of Maglev- type vehicles.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.92-98
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• 1999

Dynamic behavior of missile which is fired in canister is analyzed by flexible multibody dynamics. The bending elasticity of missile is very important in case that missile is fired in the inclined launcher. In this paper, the force element model for the missile launching stage and the finite element model of missile are developed. The FEA model of missile is condensed into five lumped mass element model and the consistence between FE model and lumped mass model of missile is verified by modal analysis. As a result of analysis, sabot reaction force and pitch rate of missile for the variation of gap size and force element are obtained.

• 소음진동
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• 제6권3호
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• pp.287-296
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• 1996

A virtual work form of flexible multibody dynamic formulation with rotary inertia has been derived. For the analysis of large flexible multibody systems, deformation modal coordinates have been employed to represent coupled motion between gross and vibrational motion. For the efficient evaluation of the entries in the mass matrix, a flexible body has been treated as a collection of mass points. The rotary inertia was generated from the consistent mass matrix in a finite element model. Deformation mode shapes were obtained from finite element analysis. Bending and twisting vibration analyses of a cantilever have been carried out to see rotary inertia effects. A space flexible robot simulation has been also carried out to show effectiveness of the proposed formulation. This formulation is effective to the model that consists of beam, plate, or shell element that contains rotational degree of freedom at the nodal point. It is also effective to the flexible body model to which a large lumped rotary inertia is attached.

• 대한기계학회논문집A
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• 제35권12호
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• pp.1579-1584
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• 2011

본 논문에서는 파도의 에너지를 전기에너지로 변환하는 파력발전시스템에 대해 다루며, 발전기 및 12개의 암을 가진 가동물체형 파력발전기를 기구학적 구속조건을 이용하여 다물체 동역학 모델링 하였다. 새롭게 제안하는 파력발전기의 기어 메커니즘과 구속방정식 및 전달되는 힘요소에 대해 동역학적으로 모델링하였다. 파력은 시간영역에서 모리슨 방정식을 이용하여 수치적으로 계산하여 모델에 적용하였다. 시스템 거동해석을 위해 상용 다물체동역학 해석프로그램인 MSC/ADAMS를 이용하였다. 파력발전시스템의 파도에 대한 안정성을 검토하고 동적 거동 특성을 분석하였다. 하중에 따라 거동 특성을 분석한 결과 Yaw 운동은 상대적으로 적게 나타났으며 파고 1 m 이상일 경우 충분한 운동에너지가 발생함을 알 수 있다.

• International Journal of Precision Engineering and Manufacturing
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• 제6권4호
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• pp.21-25
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• 2005

In the dynamic analysis of a mechanism, if one or more of the components are flexible, then the simulation will not be accurate because of the violation of the rigid body assumption. Mode shapes are used to represent the dynamic behavior of an elastic structure. A modal synthesis method which uses a combination of normal modes, constraint modes, and attachment modes, was used to represent effectively the elastic deformation of a flexible multibody. Since the combination of these modes should be different for each type of connecting part, the modal synthesis method was studied for the various types of interconnecting joints. In addition, the analysis procedure for the flexible body was explained. A satellite system with flexible solar panels was chosen as an example to show the effectiveness of the proposed method.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.36-44
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• 2019

Variable displacement swash plate piston pump analysis requires electric, hydraulics and dynamics which are similar to the one's incorporated in the complex fluid power and mechanical systems. The main variable capacity for the swash plate piston pumps, hydraulics or simple kinematic (swash plate degree, piston displacement) models are analyzed using AMESim, a multi-physics analysis program. AMESim is a multi-physics hydraulic analysis program that is considered good for the environment but not appropriate for environmental analysis for multibody dynamics. In this study, the analytical model of the swash plate type hydraulic piston pump variable capacity is modeled by combining the hydraulic part and the dynamic part through co-simulation of multibody dynamics program (Virtual.lab Motion) and multi-physics analysis (AMESim). This paper describes the whole modeling analysis method on the mechanical analysis of the multi-body dynamics program and how the hydraulic analysis in multi-physics analysis program works. This paper also presents a methodology for analyzing complex fluid power systems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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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.