• 한국산업융합학회 논문집
• /
• 제6권2호
• /
• pp.141-147
• /
• 2003

In this paper, the vibration characteristics of a linear stepping motor(LSM) are analyzed using the finite element method(FEM : Flux2D) and ACSL. A magnetic equivalent circuit is based on the structure of the LSM, and then the electric equivalent circuit of the LSM is derived by solving equations for the magnetic equivalent circuit. A normal force is calculated using FEM. And the vibration characteristics of the LSM are simulated by the ACSL with the voltage equations, the thrust equations, the normal force equations and the kinetic equations, and are measured by LASER experimental system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 A
• /
• pp.15-17
• /
• 1998

The position of LPM's mover can be estimated by the equivalent inductance variation with the mover's displacement. Hence, in this paper, we obtained the position detection signal by the calculation of equivalent inductance variation using the winding of linear pulse motor. And the various parameters for calculation of equivalent inductance variation were obtained by the design specification and finite element analysis of linear pulse motor. With this position signal, it is possible to calculate the driving numbers of steps, to confirm the state of step out and to determine the optimal switching angle, etc.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
• /
• pp.98-107
• /
• 2000

Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential for the seismic design to perform the ground response analysis In this study, ground response analyses based on the equivalent linear method were carried out to evaluate the effects of various ground conditions on the site amplification. Four major factors including the depth of the site(very soft and dense soil), the impedance ratio between soil layer and bed rock, linear analysis versus equivalent linear analysis, and the location of soft soil layer were deeply discussed. Based on the analysis results, the importance of various local site conditions on the site amplification was emphasized.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제49권6호
• /
• pp.371-379
• /
• 2000

The 4-pole linear homopolar synchronous motor (LHSM), so called linear inductor motor, is composed of the figure-of-eight shaped 3-phase armature windings, DC field windings, and the segmented secondary with the transverse bar track. To reduce the calculation time, the simplified 3D finite element model with equivalent reluctance and/or permanent magnet is presented. To obtain a clear understanding, propriety and usefulness of the developed model, we compare with the results of simplified 3D FEA, general 3D FEA and test. Consequently, the results of simplified and 3D FEM analysis are nearly identical, but much larger than that of static test at d-axis armature excitation. Therefore the improved FEA model, such as full model with half slot, is needed for the precise analysis.

• Journal of Electrical Engineering and Technology
• /
• 제13권4호
• /
• pp.1596-1603
• /
• 2018

This paper presents the new design and validation process of the linear transverse flux machine of the stelzer machine for hybrid vehicle application. A linear transverse flux machine is a novel electric machine that has higher force density and power than conventional electric machine. The process concentrates on 2-dimensional and 3-dimensional analysis using equivalent magnetic circuit method considering leakage elements and it is verified by finite element analysis. Besides the force characteristics of all axis of each direction are analyzed. The study is considered by dividing the transverse flux electric excited type and the transverse flux permanent magnet excited type. Additionally three-dimensional analysis in this machine is accomplished due to asymmetric structure with another three axes. Finally, it suggests the new design and validation process of linear transverse flux machine for stelzer machine.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1162-1164
• /
• 2005

A Linear Induction Motor that generates the direct thrust directly, is widely used for the operation system of electrified railroad, elevation system, conveyer system, and so on. There are two analysis methode of linear induction motor characteristics. One is the electrical magnetic analyzing, the other is analyzing equivalent circuit. The electrical magnetic analyzing methode has available advantages to consider the physical condition. The equivalent circuit analyzing methode has the elementary methode in the system of vector control and over shoot situation. In this paper, It is used the dynamic characteristic analyzing methode that can calculate efficiently the end effect by using equivalent circuit methode in the operating linear induction motor system modeling and doing simulation of output characteristics of vector controller.

• 대한수학회지
• /
• 제35권2호
• /
• pp.259-268
• /
• 1998

In this paper the stochastic multiple objective programming problems where the right-hand-side of the constraints is stochastic are considered. We define the equivalent scalar-valued problem and study the stability of the equivalent scalar-valued problem with respect to the weight parameters and probability mesures under reasonable assumptions.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.694-699
• /
• 2007

The spacer grid set is a part of a nuclear fuel assembly. The set has a spring and the spring supports the fuel rods safely. Although material nonlinearity is involved in the deformation of the spring,nonlinearity has not been considered in design of the spring. Recently a nonlinear response structural optimization method has been developed using equivalent loads. It is called nonlinear response optimization equivalent loads (NROEL). In NROEL, the external loads are teansformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response no EL. The objective function is defined by minimizing the maximum stress in the spring while is limited and the support force of the spring is larger than a certain value. The results are verified by nonlinear. ABAQUS is used for nonlinear response analysis and GENESIS is employed for linear response optimization.

• 대한기계학회논문집A
• /
• 제31권11호
• /
• pp.1059-1068
• /
• 2007

Nonlinear response structural optimization is performed using equivalent loads (NROEL). Nonlinear response optimization is extremely cost because many nonlinear analyses are required. In NROEL, the external loads are transformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response field of linear analysis as that of nonlinear analysis. The primitive from of theory has been published. In this research, the theory is investigated with large scale example problems. Four examples are solved by using NROEL. Conventional optimization with sensitivity analysis using the finite difference method (FDM) is also applied to the same examples. Moreover, response surface optimization method is applied to the last two examples. The results of the optimizations are compared. In nonlinear response optimization of large scale problems, hundreds (or even thousands) of nonlinear analyses are expected to satisfy the convergence criteria. However, in nonlinear response optimization using equivalent loads, only tens of nonlinear analyses are required. The results are discussed and the usefulness of NROEL is presented.

• 대한조선학회논문집
• /
• 제29권2호
• /
• pp.60-65
• /
• 1992

불규칙 해상에서 횡파중 선체의 횡요 운동 응답을 threshold crossing 과정의 관점에서 연구하였다. 비 백색 잡음 기진력은 응답의 crossing 성질이 유지되는 크기의 백색 잡음 기진력으로 대치할 수 있다는 가정하에 등가의 백색 잡음 기 진력으로 모델링 하였고 원래의 비선형 감쇄 함수를 복원하였다. 등가의 백색 잡음 기진력을 가지고 복원된 운동방정식으로부터 결합 확률 밀도 함수를 얻기 위해 등가 비선형화법(equivalent non-linearization method)을 사용하였다. 제시된 방법을 각종 계수들의 값을 변화시키면서 예측하고 이를 다른 논문의 결과와 비교하였다.