• 한국해양공학회지
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• 제14권1호
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• pp.67-73
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• 2000

The dynamic behavior of a moving elastic body system with three constant velocitics on a simple beam with an axial load is analyzed by numerical method. A moving elastic body system is composed of an elastic body and a suspension unit with two unsprung masses. The governing equations are derived with an aid of Lagrange's equation. These equation are solved by Runge-Kutta method. The damping coefficients a spring constants of the suspension unit the force circular frequency on a moving elastic body the velocity of a moving elastic body system. These effects are more important in the high modes of a simple beam.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.47-54
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• 2003

The rotating of rotatory unit with its structural unbalance mass and laundry is making the main vibration problem in a vertical axis washing machine. For reducing vibration problem total washing system hung on the case by its suspension system which is constitute of spring, damper and suspension bar and hydraulic balancer is attached at the upper rim of spin basket. In this paper, we make the dynamic model of washing system of its rigid body motions by 6 degree of freedoms. Hydraulic balancer is modeled by one degree of freedom like auto ball balancer. Elastic motions of washing system have found by method of analytic, experimental and FEM. And we consider first bending mode of each suspension bar and first circumferential mode of assy tub. So, the total washing system is modeled by 12 degree of freedoms. Equations of motion for total washing system have derived, and we perform the dynamic simulation tests.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.110-123
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• 2000

In this Study, the dynamic equation for vibration analysis of mechanical systems with kinematic constraints is derived. This equations are derived in terms of small displacements of Cartesian coordinates, and are applied to compute the dynamic response and the natural modes of the suspension system of a vehicle. The results are validated through the comparison with the results from conventional nonlinear dynamic analysis and modal test.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.216-223
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• 1999

This study was intended to determine the inertia , damping and stiffness properties of the cab-suspension of agricultural tractors by applying the direct system identification method (DSIM). Since the rigid and elastic modes of the cab-suspension are not likely to be separated clearly, direct application of the DSIM may result in large computation error. To solve such a problem, a method of locating mass center of the cab were determined by assuming the behavior of the cab-suspension is a rigid body motion. The dynamic parameters of the cab-suspension were then determined by applying the DSIM with the known coordinates of the mass center. The constraints of spatial matrices of the cab-suspension also make the algorithm for the DSIM perform better. The values of dynamic parameters determined by this method agreed well with those determined by the experiment.

• International Journal of Automotive Technology
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• 제6권4호
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• pp.375-381
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• 2005

This paper presents linear algebraic equations in the form of recursive formula to compute elastokinematic characteristics of a suspension system. Conventional methods of elastokinematic analysis are based on nonlinear kinematic constrant equations and force equilibrium equations for constrained mechanical systems, which require complicated and time-consuming implicit computing methods to obtain the solution. The proposed linearized elastokinematic equations in the form of recursive formula are derived based on the assumption that the displacements of elastokinematic behavior of a constrained mechanical system under external forces are very small. The equations can be easily computerized in codes, and have the advantage of sharing the input data of existing general multi body dynamic analysis codes. The equations can be applied to any form of suspension once the type of kinematic joints and elastic components are identified. The validity of the method has been proved through the comparison of the results from established elastokinematic analysis software. Error estimation and analysis due to piecewise linear assumption are also discussed.

• Structural Engineering and Mechanics
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• 제50권2호
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• pp.215-229
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• 2014

Due to the lack of effective longitudinal constraint for center tower, structural stiffness of three-tower suspension bridge becomes less than that of two-tower suspension bridge, and therefore it becomes more susceptible to the seismic action. By taking a three-tower suspension bridge-the Taizhou Highway Bridge over the Yangtze River with two main spans of 1080 m as example, structural dynamic characteristics and seismic performance of the bridge is investigated, and the effects of cable's sag to span ratio, structural stiffness of the center tower, and longitudinal constraint of the girder on seismic response of the bridge are also investigated, and the favorable structural system is discussed with respect to seismic performance. The results show that structural response under lateral seismic action is more remarkable, especially for the side towers, and therefore more attentions should be paid to the lateral seismic performance and also the side towers. Large cable's sag, flexible center tower and the longitudinal elastic cable between the center tower and the girder are favorable to improve structural seismic performance of long-span three-tower suspension bridges.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.25-30
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• 2006

This study is about an optimum design to improve the kinematic and compliance characteristics of a torsion-beam suspension system. The kinematic and compliance characteristics of an initial design of the suspension was obtained through a roll-mode analysis. The objective function was set to minimize within design constraints. The coordinates of the connecting point between the torsion-beam and the trailing arm were treated as design parameters. Since the torsion-beam suspension has large nonlinear effects due to kinematic and elastic motion, Genetic Algorithms were employed for the optimal design. The optimized results were verified through a double-lane change simulation using the full vehicle model.

• 한국지구과학회지
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• 제23권6호
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• pp.507-513
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• 2002

유성일대 화강암, 팔당일대 호상 편마암 및 사북일대 퇴적암 지역에서 동탄성계수와 탄성파 속도와의 관계를 밝히기 위하여 완전파형음파검층을 통해 이들 암상에서 탄성파 P파와 S파 속도를 측정하였다. 또한 유성일대 화강암과 팔당일대 편마암 지역에 대해서는 일축압축강도와 포아송비를 실내시험에서 측정하였다. 실내실험 자료에서는 팔당 호상편마암 지역의 탄성파 P파 및 S파 속도가 유성의 화강암 지역보다 높게 나타난 반면, 포아송비가 낮은 값을 보이므로 포아송비의 증가함에 따라 탄성파 P파 및 S파 속도가 감소하는 상관관계를 보였다. 완전파형음파검층을 통하여 얻어진 동탄성계수는 동체적탄성계수와 동전단탄성계수에 비하여 높은 값을 보인다.

• 대한기계학회논문집
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• 제12권3호
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• pp.450-456
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• 1988

본 연구에서는 자동차의 동력학적 해석을 위한 특별프로그램을 만들어서 범용 프로그램인 DADS와 효율성을 비교해 보고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.189-194
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• 2004

As a disk drive becomes widely used in portable environments, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes In contact with outer shock disturbance, the system gets critical damage in head-gimbal assembly or disk. This paper describes analysis of a HGA(head-gimbal assembly) in micro MO drives to shock loading during both non-operating state and operating state. A finite element model which consists of the disk, suspension, slider and air bearing was used to find structural response of micro MO drives. In the operational case. the air bearing is approximated with four linear elastic springs. The commercially available finite element solver, ANSYS/LS-DYNA, is used to simulate the shock response of the HGA in micro MO drives. In this paper, the mechanical robustness of the suspension is simuiated considering the shock responses of the HGA.