• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.11
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• pp.749-756
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• 2000

Detent force develops generally undesirable effect that contributes to the output ripple of machine, vibration and noise. This paper proposes detent force minimization techniques for a Permanent Magnet Linear Synchronous Motor (PMLSM). In addition, thrust according to each minimization technique is estimated to observe the change of machine performance. A two-dimensional Finite Element Method is used to predict detent force and thrust due to structural factors and non-linearity. And moving node technique for geometric models is proposed to reduce modeling time and efforts.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.277-285
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• 1998

This paper presents the deformation characteristics of the moving pressure plate in a balanced type vane pump that widely used automotive power steering systems. Moving pressure plate can control the clearance between rotor and plate in accordance with load pressure variation; it always guarantees that pump to have optimal volumetric efficiency. In this paper, firstly, we calculate the acting force on the pressure plate, which is used to determine the angular position and load condition for analyzing the deformation of pressure plate. Secondary, finite element method is used for the deformation analysis. As results of acting force analysis, it is found that maximum difference of forces occurs at angular position 28$\circ$ from the small arc center of cam ring and load pressure is a dominant factor to affect acting force variation. The deformation of pressure plate increases as load pressure increases. At high load pressure, the deformation of pressure plate becomes larger than the initial clearance between rotor and plate. Therefore, it is required to design the plate for controlling the deformation.

• Structural Engineering and Mechanics
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• v.13 no.2
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• pp.211-230
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• 2002

The objective of this study is to investigate the dynamic behavior of elastic beams subjected to moving loads. Although analytical methods are available, they have limitations with respect to complicated structures. The use of computer technology in recent years is an effective way to solve the problem; thus using the latest technology this study establishes a finite-element solution procedure to investigate dynamic behaviors of a typical elastic beam having a set of constant geometric properties and various span lengths. Both the dead load of the beam and traffic load are applied in which the traffic load is considered a concentrated moving force with various traveling passage speeds on the beam. Dynamic behaviors including deflection, shear, and bending moment due to moving loads are obtained by both analytical and finite element methods; for simple structures, they have an excellent agreement. The numerical results show that based on analytical methods the fundamental mode is good enough to estimate the dynamic deflection along the beam, but is not sufficient to simulate the total response of the shear force or the bending moment. The linear dynamic behavior of the elastic beams subjected to multiple exciting loads can easily be found by linear superposition, and the geometric nonlinear results caused by large deformation and axial force of the beam are always underestimated with only a few exceptions which are indicated. In order to make the results useful, they have been nondimensionalized and presented in graphical form.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2713-2716
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• 2003

This paper presents a dynamic manipulability analysis method of the limb moving in viscous fluid. The key idea of the presented method is that the boundary of joint velocity can be converted to the velocity-dependant dynamic manipulability polytope through the coriolis, centrifugal and drag terms in dynamic equation. The velocity-dependant dynamic manipulability polytope is added to the inertial and restoring force manipulability polytope to get overall manipulability polytope of the limb moving in the fluid Each of the torque and velocity bounds arc considered in the infinite norm sense in joint space, and the drag force of a limb moving in fluid viscous is modeled as a quadratic form An analysis example with proposed analysis scheme is presented to validate the method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1159-1162
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• 1995

In the continuous process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction plays a major role in the determination of the traction force between the moving web and the rollers. In this paper, a procedure to determine the frcition coefficient between the moving web and rollers is devoloped. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operating web tension and wrap alngle increase.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1255-1260
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• 2004

A moving-magnet type pickup actuator has an assembly error. That is, the actuating Part of an actuator is shifted from initial position after we assemble it into yoke. This Is the result of an effect of magnetic force between magnet and yoke. We performed magnetic-analysis using FEA. As a result of simulation, we improved the assembling efficiency for moving-magnet type actuator.

• Structural Engineering and Mechanics
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• v.38 no.1
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• pp.81-97
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• 2011

In this research, the wavelet transform is used to analyze time response of a cracked beam carrying moving mass for damage detection. In this respect, a new damage detection method based on the combined use of continuous and discrete wavelet transforms is proposed. It is shown that this method is more capable in making damage signature evident than the traditional two approaches based on direct investigation of the wavelet coefficients of structural response. By the proposed method, it is concluded that strain data outperforms displacement data at the same point in revealing damage signature. In addition, influence of moving mass-induced terms such as gravitational, Coriolis, centrifuge forces, and pure inertia force along the deflection direction to damage detection is investigated on a sample case. From this analysis it is concluded that centrifuge force has the most influence on making both displacement and strain data damage-sensitive. The Coriolis effect is the second to improve the damage-sensitivity of data. However, its impact is considerably less than the former. The rest, on the other hand, are observed to be insufficient alone.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.356-361
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• 2004

A moving-magnet type pickup actuator has an assembly error . That is, the actuating part of an actuator is shifted from initial position after we assemble it into yoke. This is the result of an effect of magnetic force between magnet and yoke. We performed magnetic-analysis using FEA. As a result of simulation, we improved the assembl ing efficiency for moving-magnet type actuator.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.990-995
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• 2008

During the ship's construction process, most high place workings have been carried out by human power, like welding, grinding and so on. Because of the ability to relieve human beings from these, the need of developing a hull-plate moving robot has been rising. This paper describes a hull-plate moving robot, using magnet modules as the adhesive method. Magnet modules maintain the magnetic force between hull-plate and magnets constantly. So that allows the robot to perform movements on the curved plate without the loss of adhesive force. The robot consists of driving motors, control system and magnet modules. The performance of the robot is verified on the curved plate.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.688-692
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• 2000

This study proposed design parameters of opening spring of circuit breaker that cut off the over-current in order to protect the electric device about opening speed using the energy method. We simulated the opening kinetic energy, the potential energy of opening spring and the design parameters of opening spring with respect to opening speed of VCB (Vacuum Circuit Breaker)'s moving contactor which has 24kV 25kA break capacity. From the result of simulation the initial tensional force and the final tensional force of the opening spring chose 107kgf and 282kgf respectively. Through the dynamic analysis using ADAMS, We verified that the opening speed of moving contactor satisfied break capacity of VCB and analyzed opening dynamic characteristics of VCB such as the opening displacement, the opening velocity and the opening acceleration of moving contactor in time domain.