• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.322-324
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• 1998

This paper describes the characteristics analysis of surface permanent magnet linear synchronous motor with conductive sheet secondary using time-stepped finite element method. The detent force, normal force, back-emf and dynamic characteristics as speed, thrust and current are described.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.760-762
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• 2000

Hybrid type LPM can be widely applied in the precise position controlled devic because precise linear motion can be directly obtained by the simple control circuit without backlash in the rotary-type stepping motor. Also, LPM can increase the Position resolution, which was limited by mechanical manufacturing limit and characteristic of magnetic material. using micro-step drive method to decrease the noise and vibration further. Especially, Double-side LPM may be replaced the solenoid as the valve driving device without difficulty and give full play to control the valve accurately. Hence, In this paper, magnetic circuit of double-side LPM was confirmed and static thrust force curve according to the relative displacement between stator and mover, was analyzed by the two dimensional finite element method. From this results, we can suppose the excitation current to be controlled optimally.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.891-893
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• 2000

Because of linear operation by direct drive and compact system, and the free accumulation of position error, LPM is suitable for proportional control valves actuator. In this study, to develop electromagnetic proportional valves actuator we designed tooth shape of double sides LPM and suggested the driving principle based upon the excitation method, It's the magnetic structure is so complex by the cubic effect configuration that finite element analysis is required. By the 3D finite element analysis, we got the magnetic distribution of LPM and analyzed static thrust force characteristics. By this analyzation, we obtained basic data required for the practical use of driving system for the proportional control valves. Thus, considering electrical and mechanical constants we could design and manufacture double sides LPM for the proportional control valves.

• 대한전기학회논문지
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• 제39권5호
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• pp.453-461
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• 1990

In this paper, a short primary-short secondary single-sided linear induction motor which is used as the driving source for an automatic conveyor system, is selected as an analysis model. The finite element method in which the current vector potential is introduced is adopted to analyze the eddy current distribution and thrust force which are produced according to the relative position of the primary and the secondary. Also, the analysis results are compared with experimental ones, to show the propriety of this model.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권2호
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• pp.53-58
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• 2001

This paper describes a moving mesh technique for dynamic characteristics analysis of permanent magnet linear synchronous motor with the secondary aluminium sheet. The moving mesh technique applied to the linear induction motor can be used to analyze the linear synchronous motor with the rectangular permanent magnet. But in case of the permanent magnet with taper, the shape of the permanent magnet is presented. The time-stepped finite element method is used for the dynamic characteristics simulation of the permanent magnet linear synchronous motor, The results of application example(hysteresis current controlled inverter fed control) such as thrust, current and flux plots are shown.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.232-234
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• 2000

Double-side LPM may be replaced the solenoid as the valve driving device with out difficulty and give full play to control the valve accurately. Double-side LPM's magnetic structure is so complex by the cubic effect configuration that finite element analysis is required. Thus, in this paper, by 2D and 3D finite element analysis, we get the flux distribution and static thrust force curves of designed double side LPM.

• 융복합기술연구소 논문집
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• 제7권2호
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• pp.1-5
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• 2017

The rotating electrodynamic wheel over a conductive plate produces thrust force as well as normal force. Specially, separating the conductive plate and spacing apart each part, the lateral stability of the rotating wheel is guaranteed due to the restoring force into neutral position. In this paper, the force characteristics of the electrodynamic wheel rotating over the conductive plate is analyzed using the finite element tool. First, the dominant parameters are identified considering the geometric configuration and the operating condition. And the sensitivity for the parameter deviation is quantified for the high force density. The above topology can be applied as an actuating principle for inter-city train as well as contact-free transfer device.

• Structural Engineering and Mechanics
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• 제89권1호
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• pp.47-59
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• 2024

In this study, a new sustainable material was proposed to prepare precast tunnel lining segments (TLS), which were produced using a fiber-reinforced slag-based geopolymer composite. Slag was used as the geopolymer binder. In addition, polypropylene and carbon fibers were added to reinforce TLSs. TLSs were examined in terms of flexural performance, load-deflection response, ductility, toughness, crack characteristics, and tunnel boring machine (TBM) thrust force. Simultaneously, numerical simulation was performed using finite element analysis. The mechanical characteristics of the geopolymer composite with a fiber content of 1% were used. The results demonstrated that the flexural performance and load-deflection response of the precast TLSs were satisfactory. Furthermore, the numerical results were capable of predicting and realistically capturing the structural behavior of precast TLSs. Therefore, fiber-reinforced slag-based geopolymer composites can be applied as precast TLSs.

• 한국전자통신학회논문지
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• 제7권5호
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• pp.1067-1072
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• 2012

현재 선형 전동기는 많은 연구가 진행되어 그 응용분야가 산업전반에 확대되고 있다. 이중 반송장치 분야에서 영구자석 선형 동기 전동기(Permanent Magnet Linear Synchronous Motor:이하 PMLSM)가 각광을 받고 있다. 영구자석 선형 동기 전동기는 구조적으로 간단하며 고속화 고추력화 등의 장점을 가지고 있지만 전기자를 반송경로 전장에 배치하는 지상 1차측 시스템을 장거리 반송장치에 적용하면 재료비용의 증가 및 제작시간 증가 등의 문제점이 발생한다. 따라서 전기자를 분산(불연속) 배치하는 방식이 제안되고 있다. 하지만 이러한 전기자 분산배치 방식은 구조적으로 단부가 존재하고 이러한 단부에 의해 코깅력이 발생한다. 이는 추력 맥동의 원인이 되며, 소음과 진동을 발생시킨다. 따라서, 본 연구에서는 전기자를 분산배치 할 경우 필연적으로 생기는 단부에 의한 코깅력을 저감하기 위해 Bifurcating을 적용한 집중권 PMLSM에 보조극 설치법을 제안한다. 또한 그에 따른 단부 코깅력 특성을 2차원 유한요소법(FEA)을 이용하여 분석하였다.

• Journal of Ship and Ocean Technology
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• 제10권4호
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• pp.1-11
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• 2006

The finite volume based multi-block RANS code, WAVIS developed at MOERI is applied to the numerical self-propulsion test. WAVIS uses the cell-centered finite volume method for discretization of the governing equations. The realizable $k-{\epsilon}$ turbulence model with a wall function is employed for the turbulence closure. The free surface is captured with the two-phase level set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. The propeller forces are obtained using an unsteady lifting surface method based on potential flow theory. The numerical procedure followed the self-propulsion model experiment based on the 1978 ITTC performance prediction method. The self-propulsion point is obtained iteratively through balancing the propeller thrust, the ship hull resistance and towing force that is correction for Reynolds number difference between the model and full scale. The unsteady lifting surface code is also iterated until the propeller induced velocity is converged in order to obtain the propeller force. The self-propulsion characteristics such as thrust deduction, wake fraction, propeller efficiency, and hull efficiency are compared with the experimental data of the practical container ship. The present paper shows that hybrid RANS and potential flow based numerical method is promising to predict the self-propulsion parameters of practical ships as a useful tool for the hull form and propeller design.