• Title, Summary, Keyword: Structural Characteristic Analysis

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A Study on the Characteristics Analysis According to the Permanent Magnet Segmentation Change to IPMSM for Urban Railway Vehicle (도시철도차량용 IPMSM의 Magnet Segment 변화에 따른 특성 분석에 관한 연구)

  • Jeong, Geochul;Park, Chan-Bae;Jeong, Taechul;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.10
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    • pp.1486-1492
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    • 2015
  • The following study carried out the characteristic analysis based on the magnet segment of Interior Permanent Magnet Synchronous Motor(IPMSM) for the urban railway vehicles. IPMSM affects the electromagnetic characteristics through the change in magnetic flux based on the rotor structure, and significantly influences the structural features through the change of pressure. Therefore, satisfied by the demanded traction force of the IPMSM, magnet segment derived three different model types. The 1-segment PM model consisted an undivided permanent magnet. The 2-Bridge model consisted a divided permanent magnet with the application of Bridge. The 3-Bridge model consisted additional dividing with one more Bridge applied. The electromagnetic characteristics of the three models were compared and analyzed along with the structural features regarding the scattering of permanent magnet based on strong centrifugal force from the rotation of the rotor at high speed. In conclusion, the final model with electromagnetic characteristics and structural features most suitable of IPMSM for the urban railway vehicles was derived, and the effectiveness was verified through the characteristic experiments after the production of the derived model.

Stability study on tenon-connected SHS and CFST columns in modular construction

  • Chen, Yisu;Hou, Chao;Peng, Jiahao
    • Steel and Composite Structures
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    • v.30 no.2
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    • pp.185-199
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    • 2019
  • Modular construction is an emerging technology to accommodate the increasing restrictions in terms of construction period, energy efficiency and environmental impacts, since each structural module is prefabricated offsite beforehand and assembled onsite using industrialized techniques. However, some innate structural drawbacks of this innovative method are also distinct, such as connection tying inaccessibility, column instability and system robustness. This study aims to explore the theoretical and numerical stability analysis of a tenon-connected square hollow section (SHS) steel column to address the tying and stability issue in modular construction. Due to the excellent performance of composite structures in fire resistance and buckling prevention, concrete-filled steel tube (CFST) columns are also taken into account in the analysis to evaluate the feasibility of adopting composite sections in modular buildings. Characteristic equations with three variables, i.e., the length ratio, the bending stiffness ratio and the rotational stiffness ratio, are generated from the fourth-order governing differential equations. The rotational stiffness ratio is recognized as the most significant factor, with interval analysis conducted for its mechanical significance and domain. Numerical analysis using ABAQUS is conducted for validation of characteristic equations. Recommendations and instructions in predicting the buckling performance of both SHS and CFST columns are then proposed.

Thermal denaturation analysis of protein

  • Miyazawa, Mitsuhiro
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • pp.1628-1628
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    • 2001
  • Near infrared (NIR) spectroscopy is a powerful technique for non-destructive analysis that can be obtained in a wide range of environments. Recently, NIR measurements have been utilized as probe for quantitative analysis in agricultural, industrial, and medical sciences. In addition, it is also possible to make practical application on NIR for molecular structural analysis. In this work, Fourier transform near infrared (FT-NIR) measurements were carried out to utilize extensively in the relative amounts of different secondary structures were employed, such as Iysozyme, concanavalin A, silk fibroin and so on. Several broad NIR bands due to the protein absorption were observed between 4000 and $5000\;^{-1}$. In order to obtain more structural information from these featureless bands, second derivative and Fourier-self-deconvolution procedures were performed. Significant band separation was observed near the feature at $4610\;^{-1}$ ,. Particularly the peak intensity at $4525\;^{-1}$ shows a characteristic change with thermal denaturation of fibroin. The structural information can be also obtained by mid-IR and CD spectral. Correlation of NIR spectra with protein structure is discussed.

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Structural Design for Performance Improvement of Line Center (라인센터의 성능향상을 위한 구조설계)

  • Cheong, Seon-Hwan;Choi, Seong-Dae;Kweon, Hyun-Kyu;Choi, Un-Don;Shon, Jae-Yool
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.2 no.3
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    • pp.76-83
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    • 2003
  • Recently, the field of the engineering has been studied about optimum design continuously. Verified data by comparison with simulation and dynamic characteristic analysis enables the design of a machine tool to be modified easily and effectively concerning to the mode shape of the vibration. Especially, BC-500 Line Center has got some problems causing vibration which mainly come from Column and ATC part. So it is necessary to solve those problems by the two kinds of method such as changing structural design and reinforcing with ribs. In this paper, column and ATC part of BC-500 Line center are modified by an optimum design by the analysing method of FEM to avoid vibration. As a result, a more stable machine tool was designed by this simulation as optimum condition.

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Characteristic Analysis of Particulate Composites According to a Random Microstructure (랜덤 미세구조에 따른 입자 복합재료의 특성분석)

  • Park, Cheon;Kang, Young-Jin;Noh, Yoojeong;Lim, O-Kaung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.1
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    • pp.23-30
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    • 2017
  • Since shape, size and distribution of particles in particulate composites have spreaded characteristics, properties of particulate composites have variation and also system behavior using particulate composites have variation. However, it is difficult to consider spreaded characteristic of particles so that a system behavior is analysed using homogeneous techniques or using microstructure in local areas. In this study, for considering random variation of particles, RMDFs(random morphology description functions) are used to generate random microstructure and relationship between the number of gaussian functions and spreaded characteristic of particles was analysed using the geometrical moment of area. Also, multi-scale analysis was carried out for cantilever beam with full-random microstructure to study behavior of particulate composites structure. As a result, it is defined that spreaded characteristic of particles and the variation of deflections of cantilever beam are decreased as the number of Gaussian functions(N) is increased and converges at N=200.

Dynamic Characteristic Analysis of Water Jet Loom Driving System (워터제트직기 구동시스템의 동특성 해석)

  • Kim, Sang-Yoon;Park, Dae-Kyu;Chun, Du-Hwan;Park, Myung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.5
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    • pp.459-464
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    • 2008
  • While high speed / precision investigating for maximization of Textile Machinery business is requesting a machine which has highly endurance, stability and reliance abilities following customer request. In this research, load volume that gives influence on loom is measured and analyzed for water jet loom in real operation time to driving system adhered torque sensor to each a module. As well, measurement and analysis technology are developed about torque and vibration of driving systems for textile machinery by comparing dynamical analysis of water jet loom with gained result, basic materials about development of high value added textile machinery which has endurance and stability are presented.

A Study on the Stabilizing Process and Structural Characteristics of Cable-Dome Structure (케이블돔 구조물의 안정화 이행과정 및 구조적 거동특성에 관한 연구)

  • 한상을;이경수;이주선;황보석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.260-267
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    • 1999
  • In this paper, We propose the initial shape finding and dynamic analysis of cable dome structure are presented. Cable dome that is consist of three component such as cable, strut and fabric membrane have complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system, and fabric membrane element Is conceived as cladding roof material. One of the important problem of cable dome is shape finding of those subjected to cable and membrane forces, which stabilize the structures. And the other is structural response from external load effect such as snow and wind When cable dome are subjected to dynamic load such as wind load each structural component has many important problem because of their special structural characteristics. One problem is that geometrical nonlinearity should be considered in the dynamic analysis because large deformation is occurred from their flexible characteristic. The other problem is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper describe the physical structural response of cable dome structure.

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A structural health monitoring system based on multifractal detrended cross-correlation analysis

  • Lin, Tzu-Kang;Chien, Yi-Hsiu
    • Structural Engineering and Mechanics
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    • v.63 no.6
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    • pp.751-760
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    • 2017
  • In recent years, multifractal-based analysis methods have been widely applied in engineering. Among these methods, multifractal detrended cross-correlation analysis (MFDXA), a branch of fractal analysis, has been successfully applied in the fields of finance and biomedicine. For its great potential in reflecting the subtle characteristic among signals, a structural health monitoring (SHM) system based on MFDXA is proposed. In this system, damage assessment is conducted by exploiting the concept of multifractal theory to quantify the complexity of the vibration signal measured from a structure. According to the proposed algorithm, the damage condition is first distinguished by multifractal detrended fluctuation analysis. Subsequently, the relationship between the q-order, q-order detrended covariance, and length of segment is further explored. The dissimilarity between damaged and undamaged cases is visualized on contour diagrams, and the damage location can thus be detected using signals measured from different floors. Moreover, a damage index is proposed to efficiently enhance the SHM process. A seven-story benchmark structure, located at the National Center for Research on Earthquake Engineering (NCREE), was employed for an experimental verification to demonstrate the performance of the proposed SHM algorithm. According to the results, the damage condition and orientation could be correctly identified using the MFDXA algorithm and the proposed damage index. Since only the ambient vibration signal is required along with a set of initial reference measurements, the proposed SHM system can provide a lower cost, efficient, and reliable monitoring process.

A Study on the Dispersion Characteristics of Carbon Nanotubes using Cryogenic Ball Milling Process (극저온 볼밀링 공정을 이용한 탄소나노튜브의 분산특성 연구)

  • Lee, Ji-Hoon;Rhee, Kyong-Yop
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.7
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    • pp.49-54
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    • 2010
  • The cryogenic ball milling was performed on carbon nanotubes (CNTs) at an extremely low temperature to increase the dispersion of CNTs. The effects of milling speed and time on the deagglomeration and structural changes of CNTs were studied. FESEM was used to analyze the dispersion and the change of particle size before and after milling process. Transmission electron microscopic (TEM) analysis was also investigated the effect of cryogenic ball milling on the morphological characteristics of CNTs. The structural changes by the cryogenic ball milling process were further confirmed by x-ray diffraction (XRD) and Raman spectroscopic analysis. The results showed that the agglomeration of CNTs was significantly reduced and amorphous structure was observed at high milling speed. However, the milling time has no great effect on the dispersion property and structural change of CNTs compared with milling speed.

A Study on the Vibrational Environment Test of KSLV-1 Demonstration Satellite (한국형 위성 발사체 성능 검증위성의 진동환경에 관한 연구)

  • Seo, Hyun-Suk;Kim, Hong-Bae;Woo, Sung-Hyun;Chae, Jang-Soo;Oh, Tae-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.966-970
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    • 2005
  • On the basis of the development of KSLV-1, KoDSat was designed and manufactured to demonstrate the performance of KSLV-1. KoDSat is exposed to a severe vibrational environment at launch. The structural reliability of KoDSat has to be verified using vibrational test. The structural compatibility and verification of components between analysis and test can be proved using environmental vibration test. In this paper, we review the structural characteristic of thruster control unit for a space launch vehicle and design TCU housing using mathematical model. In order to verify the structural compatibility and reliability, half-sine shock, random and sing sweep vibration test was performed. Especially, sing sweep vibration test result is compared with analysis result and mathematical model is verified.

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