• Title/Summary/Keyword: CQC

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China's certification(CCC, CQC) of the Drive motor system for electric vehicles (전기차 구동 모터 시스템의 중국 인증(CCC, CQC))

  • Kim, Sunil;Lee, Yongkyun;Eom, Daesik;Lee, Inseok
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.425-426
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    • 2016
  • 본 논문에서는 중국 인증제도(CCC, CQC)의 의의와 절차 그리고 전기차 구동 모터 시스템의 인증해당여부 및 관련 규격을 분석한다. 분석한 규격은 중국 국가 규격인 GB/T 18488(Drive motor system for electric vehicles)을 해석한 결과이다.

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Vertical Seismic Vibration of Suspension Bridges (지진을 받는 현수교의 수직진동)

  • Choi, Jee-Hoon;Lee, Jon-Ja;Kim, Su-Bo;Lee, Yong-Jae
    • Journal of Korean Society of Steel Construction
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    • v.12 no.5 s.48
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    • pp.581-593
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    • 2000
  • In this study, vertical dynamic analyses on the suspension bridges under seismic load are developed. Time domain analysis, random vibration analysis, and spectral analysis are formulated theoretically. The random nitration analysis is checked by numerical integration and the mathematical integration with correlation coefficient which include CQC and SRSS method in the conditions of white noise and filtered white noise. Beam, truss and frame elements are used in order to model the suspension bridge. Geometric stiffness due to dead load is considered for cable and tower.

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Coupled buffeting response analysis of long-span bridges by the CQC approach

  • Ding, Quanshun;Chen, Airong;Xiang, Haifan
    • Structural Engineering and Mechanics
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    • v.14 no.5
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    • pp.505-520
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    • 2002
  • Based on the modal coordinates of the structure, a finite-element and CQC (complete quadratic combination) method for analyzing the coupled buffeting response of long-span bridges is presented. The formulation of nodal equivalent aerodynamic buffeting forces is derived based on a reasonable assumption. The power spectral density and variance of nodal displacements and elemental internal forces of the bridge structure are computed using the finite-element method and the random vibration theory. The method presented is very efficient and can consider the arbitrary spectrum and spatial coherence of natural winds and the multimode and intermode effects on the buffeting responses of bridge structures. A coupled buffeting analysis of the Jiangyin Yangtse River Suspension Bridge with 1385 in main span is performed as an example. The results analyzed show that the multimode and intermode effects on the buffeting response of the bridge deck are quite remarkable.

Probabilistic analysis of peak response to nonstationary seismic excitations

  • Wang, S.S.;Hong, H.P.
    • Structural Engineering and Mechanics
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    • v.20 no.5
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    • pp.527-542
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    • 2005
  • The main objective of this study is to examine the accuracy of the complete quadratic combination (CQC) rule with the modal responses defined by the ordinates of the uniform hazard spectra (UHS) to evaluate the peak responses of the multi-degree-of-freedom (MDOF) systems subjected to nonstationary seismic excitations. For the probabilistic analysis of the peak responses, it is considered that the seismic excitations can be modeled using evolutionary power spectra density functions with uncertain model parameters. More specifically, a seismological model and the Kanai-Tajimi model with the boxcar or the exponential modulating functions were used to define the evolutionary power spectral density functions in this study. A set of UHS was obtained based on the probabilistic analysis of transient responses of single-degree-of-freedom systems subjected to the seismic excitations. The results of probabilistic analysis of the peak responses of MDOF systems were obtained, and compared with the peak responses calculated by using the CQC rule with the modal responses given by the UHS. The comparison seemed to indicate that the use of the CQC rule with the commonly employed correlation coefficient and the peak modal responses from the UHS could lead to significant under- or over-estimation when contributions from each of the modes are similarly significant.

STANDARDS OUTLOOK 해외 기술표준동향 - 중(中), 저탄소경제의 발전방향과 대책 논의

  • Ryu, Ha-Na
    • The Monthly Technology and Standards
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    • s.119
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    • pp.44-45
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    • 2012
  • 중국품질인증센터(CQC)가 주최한 '저탄소경제 인증 서밋'이 지난 해 11월 25일 베이징에서 개최되었다. 이번 회의의 3대 주제는 '저탄소경제의 시장 메커니즘과 발전정책', '지속가능한 발전을 촉진하는 에너지전략', '저탄소경제에서 저탄소 인증 및 표준화의 역할'이다.

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Seismic Analysis of Building Structures with Ambiguous Modal Direction (모드의 방향이 불분명한 건축구조물의 지진해석)

  • 김태호;이동근;김대곤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.513-520
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    • 2002
  • This study is for seismic analysis of building structures with ambiguous modal direction This case is revealed symmetrical building structure or the structure that isn't coincided building axis with physical axis. Seismic analysis-time history analysis, response spectrum analysis and lateral force procedure-is carried out. It is concluded that analysis method for the structure with ambiguous modal direction don't suitable for lateral force procedure. It is recommended to use the CQC method for combining modal responses to the individual components and the SRSS rule for combining responses to the two horizontal components are of nearly equal intensities.

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The relationship between time-varying eccentricity of load with the corner lateral displacement response of steel structure during an earthquake

  • Takin, Kambiz;Hashemi, Behrokh H.;Nekooei, Masoud
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.801-812
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    • 2016
  • In an actual design, none of the structures with shear behaviors will be designed for torsional moments. Any failure or damages to roofs, infills, shear walls, and braces caused by an earthquake, will inevitably result in relocation of center of mass and rigidity of the structure. With these changes, the dynamic characteristics of structure could be changed during an earthquake at any moment. The main objective of this paper is to obtain the relationship between time-varying eccentricity of load and corner lateral displacement. In this study, various methods have been used to determine the structural response for time-varying lateral corner displacement. As will be seen below, some of the structural calculation methods result in a significant deviation from the actual results, although these methods include the interaction effects of modes. Controlling the lateral displacement of structure can be performed in different ways such as, passive dampers, friction dampers, semi-active systems including the MR damper and active Systems. Selecting and locating these control systems is very important to bring the maximum safety with minimum cost into the structure. According to this study will be show the relation between the corner lateral displacements of structure and time-varying eccentricity by different kind of methods during an earthquake. This study will show that the response of the structure at the corners due to an earthquake can be very destructive and because of changing the eccentricity of load, calculating the maximum possible response of system can be carried out by this method. Finally, some kind of systems must be used for controlling these displacements. The results shows that, the CQC, DSC and exact methods is comply each other but the results of Vanmark method is not comfortable for these kind of buildings.

Response Spectrum Analysis of Floor Structure Subjected to Group Dynamic Loads (복수의 동적하중을 받는 바닥판 구조물의 응답스펙트럼 해석)

  • Kim, Tae-Ho;Han, Duck-Jeon
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.1
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    • pp.57-67
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    • 2008
  • In general, the response spectrum analysis(RSA) method is wifely used for seismic analysis of building structures, and the time history analysis(THA) is applied for computation of structural vibration caused by equipments, machines and moving loads, etc. However, compared with the RSA method, the THA method is very complex, difficult and time consuming. In this study, the maximum responses for the vertical vibration are calculated conveniently by the RSA method. At first, the process for the RSA in excitation is proposed, and the maximum modal responses are combined by CQC and SRSS methods. Also, the responses obtained by the two modal combination methods are compared to the responses by the THA. And the correlation coefficients for human activities is proposed, and the RSA responses obtained by used to the correlation coefficients are calculated. Finally, results of the proposed method are compared with those of the time history analysis and correlation coefficients should be considered for the RSA of floor structure subjected to group dynamic loads.

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Direct Ritz method for random seismic response for non-uniform beams

  • Lin, J.H.;Williams, F.W.;Bennett, P.N.
    • Structural Engineering and Mechanics
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    • v.2 no.3
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    • pp.285-294
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    • 1994
  • Based on a fast and accurate method for the stationary random seismic response analysis for discretized structures(Lin 1992, Lin et al. 1992), a Ritz method for dealing with such responses of continuous systems in developed. This method is studied quantitatively, using cantilever shear beams for simplicity and clarity. The process can be naturally extended to deal with various boundary conditions as well as non-uniform Bernoulli-Euler beams, or even Timoshenko beams. Algorithms for both proportionally and non-proportionally damped responses are described. For all of such damping cases, it is not necessary to solve for the natural vibrations of the beams. The solution procedure is very simple, and equally efficient for a white or a non-white ground excitation spectrum. Two examples are given where various power spectral density functions, variances, covariances and second spectral moments of displacement, internal force response, and their derivatives are calculated and analyses. Some Ritz solutions are compared with "exact" CQC solutions.

Seismic behavior of suspended building structures with semi-rigid connections

  • Liu, Yuxin;Lu, Zhitao
    • Earthquakes and Structures
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    • v.7 no.4
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    • pp.415-448
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    • 2014
  • A method is presented in this paper to analyze the dynamic response behavior of suspended building structures. The effect of semi-rigid connections that link suspended floors with their supporting structure on structural performance is investigated. The connections, like the restrains in non-structural suspended components, are designed as semi-rigid to avoid pounding and as energy dissipation components to reduce structural response. Parametric study is conducted to assess the dynamic characteristics of suspended building structures with varying connection stiffness and suspended mass ratios. Modal analysis is applied to identify the two distinct sets of vibration modes, pendulum and bearing, of a suspended building structure. The cumulative modal mass is discussed to ensure the accuracy in applying the method of response spectrum analysis by SRSS or CQC modal combination. Case studies indicate that a suspended building having semi-rigid connections and proper suspended mass ratios can avoid local pounding failure and reduce seismic response.