• 한국산업융합학회 논문집
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• 제23권5호
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• pp.789-798
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• 2020

This paper considers the development of the dynamic analysis model and simulation-based operation safety estimation of A-Frame to be applied to the test evaluation support vessel for real sea test. The support vessel will be manufactured by modifying the existing offshore support vessel. Also, development and installation of various sensors and supporting facilities for test evaluation are under preparation. Among these facilities, A-Frame is an equipment that transfers marine equipment from ship deck to the sea floor, and is being designed to transfer up to 50 ton class equipment. However, the A-Frame is a moving equipment using hydraulic cylinders. When the 50 ton equipment is attached and transferred to A-Frame, the buckling of cylinders may occur or A-Frame becomes inoperable due to the influence of huge inertia. For this reason, safety verification should be performed using dynamic analysis techniques that can take into account huge inertia forces in the design of A-Frame. Therefore, in this study, A-Frame and ship behavior were modeled using dynamic analysis method, and the applied loads of various equipment including hydraulic cylinder of A-Frame was measured and the operation safety review was performed.

• 대한기계학회논문집
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• 제10권4호
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• pp.450-455
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• 1986

본 연구에서는 직교좌표계 및 Euler-Lagrange 방법을 이용하여 유도된 기본 방정식을 사용하여 앞창닦기기구(windshield wiper mechanism)의 동력학적 해석을 하 였다.모우터가 일정한 각속도로 회전하고 있는 경우와, 토오크가 각속도의 크기에 따라 변화하는 경우 각각에 대해서 강체로 해석할 때와 탄성체로 가정할 때의 해석결 과를 비교하였다.

• 한국철도학회논문집
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• 제2권1호
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• pp.47-55
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• 1999

In this paper, an efficient and accurate formulation for the transient analysis of constrained multibody systems is presented. The formulation employs Kane's method along with the null space method. Kane's method reduces the dimension of equations of motion by using partial velocity matrix: it can improve the efficiency of the formulation. Furthermore, the formulation partitions the coefficient matrix of linear and nonlinear equations into several sub-matrices using kinematic uncoupling. This can solve the equations more efficiently. The proposed formulation can be used to perform dynamic analysis of systems which can be partitioned into several sub-systems such as train systems. One numerical example is given to demonstrate the efficiency and accuracy of the formulation, and another numerical example is given to show its application to the train systems.

• 한국공작기계학회논문집
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• 제10권2호
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• pp.18-28
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• 2001

Super computers has been utilized to carry out vehicle dynamics in real time. This research propose an implicit integra-tion method for vehicle state variables. Newton chord method is empolyed to solve the equations of motion and con-straints. The equations of motion and constraints are formulated such that the Jacobian matrix for Newton chord method is needed to be computed only once for a dynamic analysis. Numerical experiments showed that the Jacobian matrix generat-ed at the initial time could have been utilized for the Newton chord iterations throughout simulations under various driving conditions. Convergence analysis of Newton chord method with the proposed Jacobian updating method is carried out. The proposed algorithm yielded accurate solutions for a prototype vehicle multibody model in realtime on a 400 MHz PC compatible.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.561-565
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• 2000

This paper deals with dynamic walking and inverse dynamic analysis of the IWR biped walking robot. The system has nine bodies of the multibody dynamics. and all of the .joints of them are made up of the revolute joints at first. The problem of redundant constraint in double support phase is solved by changing the type of the joints considering kinematic relation. To make sure of its dynamic walking, the movement of balancing weight is determined by which satisfies not only the condition of ZMP by applying the principle of D'Alembert but also the contact condition of the ground. The modeling of IWR and dynamic walking are realized using DADS.

• 대한기계학회논문집A
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• 제27권4호
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• pp.544-550
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• 2003

The contact analyses of arbitrary shaped spatial bodies are important in the study of multi-body dynamics. This paper presents a method fur calculating contact force between bodies in space. At each integration time step, the proposed method finds potential contact points on bodies and then calculates the penetration, the velocity of penetration, and the contact force. A continuous analysis method is adopted to calculate the contact force. To get contact points accurately on their outlines, a new algorithm is developed. The proposed algorithm is tested and compared the results of DADS. As applications, the contact of two steel balls, spatial pendulums, and the problem of a ball and bat are demonstrated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1730-1735
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• 2003

In this paper, the absolute nodal coordinate formulation was introduced to describe the large deformation problems. And also, the modal coordinates were employed to represent the small elastic deformation. A new hybrid formulation was developed to combine the modal coordinates and the absolute nodal coordinates. A spherical joint and the DOT1 constraint were developed to carry out the numerical simulation of mechanical systems with kinematic joints. A beam example was suggested to show the new formulation. The simulation results using the modal coordinates and the absolute nodal coordinates show a good agreement to the experiments.

• 대한기계학회논문집A
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• 제35권7호
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• pp.723-728
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• 2011

진공회로차단기의 성능이 스프링조작기에 많이 좌우되기 때문에, 스프링조작기의 해석이 요구된다. 본 연구에서는 스프링의 특성시험을 먼저 수행한 후, 시험결과를 RecurDyn 프로그램을 이용한 컴퓨터시뮬레이션 스프링모델링에 이용하였다. 개발된 진공회로차단기의 다물체동역학 모델을 이용하여 차단기의 스템변위와 샤프트 회전각에 대한 시뮬레이션 하였으며, 시뮬레이션 결과를 시험과 비교 검증하였다. 검증된 다물체동역학 모델을 사용하여 차단속도를 증가시키기 위한 캠의 최적윤곽을 얻었다.

• International Journal of Precision Engineering and Manufacturing
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• 제3권4호
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• pp.54-63
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• 2002

In recent years, mechanical systems such as high speed vehicles and railway trains moving on elastic beam structures have become a very important issue to consider. In this paper, a general approach, which can predict the dynamic behavior of a constrained mechanical system moving on a flexible beam structure, is proposed. Various supporting conditions for the foundation support are considered for the elastic beam structure. The elastic structure is assumed to be a non-uniform and linear Bernoulli-Euler beam with a proportional damping effect. Combined differential-algebraic equation of motion is derived using the multi-body dynamics theory and the finite element method. The proposed equations of motion can be solved numerically using the generalized coordinate partitioning method and predictor-corrector algorithm, which is an implicit multi-step integration method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.677-682
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• 2007

Recently, a precision stage is widely used in the fields of the nano technology. In this paper, the precision stage which consists of linear motor, vision system, light source system and controller, is designed and developed for nano imprint machine. Stiffness design considering resonance frequency is important for the precision stage. A virtual machine simulation is useful for machine development the early design stage. Kinematic and dynamic simulations of XYZ stage are performed. To consider the resonance frequency and vibration effects flexible multibody dynamics are utilized with FE modeling of the structural components.