• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2000년도 추계학술대회논문집
• /
• pp.153-158
• /
• 2000

The sway motion of the spreader during and after movement causes an efficiency problem of position control in unmaned gantry crane. The objective of this research is to investigate the phenomenon that the load is taken by the sway motion of crane. For deriving the dynamic equations related to the swing motion of crane, we introduced a conception of spring and damper in the upper part of the crane. During the crane and trolley is driving along the velocity profile, the swing motion of the spreader and crane will be simulated. The simulation result of the equation of motion using the Runge-Kutta method is presented in this paper. And we will show an effect of the swing of the crane in this research.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.778-782
• /
• 2004

Floating floor structure, which is mainly adopted for reducing interior noise of railway vehicle, is known that it is superior to single wall in respect of sound transmission loss. The dynamic characteristic of the support in the floating floor that is one of the important design variables in floating floor structure can change the sound and vibration insulation properties of it. From excitation test, the dynamic stiffness and loss factor of the support are evaluated. They are used as input parameter for analyzing the sound transmission loss of floating floor. Predicted transmission loss is compared with the prototype-car test results.

• 한국소음진동공학회논문집
• /
• 제14권11호
• /
• pp.1059-1065
• /
• 2004

In this paper, the dynamic characteristic analysis of carriage structure supported by air bearings were performed. Toward this end, the characteristics of air bearing were numerically analyzed to estimate the stiffness of the air bearing and the clearance between air bearing and guide surface. The modal analysis of the carriage structure was performed by using finite element method, and the experimental modal analysis was also performed to validate the finite element model, where rigid body modes were compared to validate the stiffness of the air bearings. From the results, the air spring stiffness can be estimated within the range of acceptable accuracy under any pressure and clearance condition.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.1107-1114
• /
• 2003

In this thesis, the dynamic characteristic analysis of carriage structure supported by air bearings were peformed. Toward this end, the characteristics of air bearing were numerically analyzed to estimate the stiffness of the air bearing and the clearance between air bearing and guide surface. The modal analysis of the carriage structure was peformed by using finite element method, and the experimental modal analysis was also performed to validate the finite element model, where rigid body modes were compared to validate the stiffness of the air bearings. From the results, the air spring stiffness can be estimated within the range of acceptable accuracy under any pressure and clearance condition.

• 유공압시스템학회:학술대회논문집
• /
• 유공압시스템학회 2010년도 춘계학술대회
• /
• pp.1-6
• /
• 2010

Direct Drive Valves (DDV) with electric closed loop spool position control are suitable for electrohydraulic position, velocity, pressure or force control systems including those with high dynamic response requirements. The spool drive device is a permanent magnet linear force motor which can actively stroke the spool from its spring centered position in both directions. This basic study is carried out to drive the design parameters for developing a domestic DDV. The static and dynamic characteristics of DDV are examined. The simulation results are compared with data of manufacture's catalog to show the validity of the modelling.

• 한국자동차공학회논문집
• /
• 제19권2호
• /
• pp.57-65
• /
• 2011

In this paper, a hydropneumatic modeling and dynamic analysis of a heavy truck semi-active cabin air suspension system is presented. Semi-active cabin air suspension system improves driver's ride comfort by controlling the damping characteristics in accordance with driving situation. So it can reduce vibration between truck frame and cabin. Semi-active cabin air suspension system is consist of air spring, leveling valve and CDC shock absorber, and full cabin system are mathematically modelled using AMESim software. Simulation results of components and full cabin system are compared with experimental data of components and test results of a cabin using 6 axis simulation table. It is found that the simulation results are in good agreements with test results, and the hydropneumatic model can be used well to predict dynamic characterics of heavy truck semi-active cabin air suspension system.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.723-726
• /
• 2002

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research of dynamic characteristics is very deficient. In this paper, the helical spring is fabricated with NiTi SMA wire of high resistivity The farce, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA actuator is analyzed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1577-1580
• /
• 2003

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

• 한국지열·수열에너지학회논문집
• /
• 제7권1호
• /
• pp.51-58
• /
• 2011

Due to enhanced sealing and insulation of buildings, extensive use of glasses for building envelopes and increased use of heat generating office equipments, energy consumption of modem buildings for cooling is steadily increasing. With outdoor air cooling(ODAC) system, cooling load can be reduced by exchanging indoor air with the cold outdoor air during spring and fall seasons. If ODAC is operated based only on temperature, total cooling load may virtually increase if the outdoor humidity is high. To overcome this problem, ODAC should be controlled based on enthalpy. In this work energy saving characteristics of enthalpy controlled ODAC is studied using dynamic simulation. The result shows that cooling load can be reduced by 27% by adopting ODAC.

• 한국수소및신에너지학회논문집
• /
• 제20권3호
• /
• pp.179-187
• /
• 2009

This paper presents a static and dynamic characteristics of the relief valve which is a kind of direct operated pressure control valve for hydrogen compressor. The valve is consisted of a main poppet, a spring, an adjuster and a valve body. The purpose of this study is development of the simulation model for relief valve by using commercial AMESlM$^{(R)}$ tool. Poppet with sharp edge seat type and ball poppet with sharp edge seat type compare for P-Q characteristic. The dynamic simulation results are presented the operating pressure characteristics of relief valve. High pressure power unit of which maximum pressure control range is 100MPa was manufactured, and the pressure control valve was experimented using the above-mentioned power unit. The new model of pressure control valve from this results was suggested. It was confirmed that the suggested valve has a good control performance from experimental setup.