• Title/Summary/Keyword: Expansion Method

Search Result 3,557, Processing Time 0.04 seconds

The Equations of Motion for the Stretcthing, Bending and Twisting of a Marine Pipeline Containing Flowing Fluids (내부 유체 유동을 포함한 해저 파이프 라인의 인장 굽힘 비틀림 운동 방정식)

  • 서영태
    • Journal of Ocean Engineering and Technology
    • /
    • v.8 no.2
    • /
    • pp.151-156
    • /
    • 1994
  • The equations of motion of a submarine pipeline with the internal flowing fluid and subject to hydrodynamic loadings are derived by using Hamilton's principle. Coupling between the bending and the longitudinal extension due to axial load and thermal expansion are considered. Coupling between the twisting and extension are not considered. The equations of motion are well agreed with the results which are derived by the vector method.

  • PDF

Stress Response of Cement Interface on Manufacturing Process of a Suspension Insulator (송전선용 현수애자 양생공정에서 발생하는 접착부의 응력변화)

  • Woo, Byung-Chul;Han, See-Won;Cho, Han-Goo
    • Proceedings of the KIEE Conference
    • /
    • 2003.07c
    • /
    • pp.1448-1450
    • /
    • 2003
  • The suspension insulators are subjected to harsh environment in service for a long time. Long term reliability of the insulators is required for both mechanical and electrical performances. We studied an analysing method to find out a deformation of brittle porcelain with a thermal expansion of simulation analysis and experimental results show that cement volume growths affect severely to be mechanical failure ageing.

  • PDF

Analysis of Reflection Coefficients of Random Waves Propagating over Multi-arrayed trenchs (다열 함몰지형을 통과하는 불규칙 파랑의 반사해석)

  • Kang, Gyu-Young;Jung, Tae-Hwa;Cho, Yong-Sik
    • 한국방재학회:학술대회논문집
    • /
    • 2008.02a
    • /
    • pp.213-216
    • /
    • 2008
  • In this study, reflection coefficients of regular and random waves propagating over multi-arrayed trenchs are calculated respectively. When the row of trench is 3, the reflection coefficient of regular waves is more than 0.7 as maximum value. Similarly, when the row of trench is 3 and $d/L_1$ is 0.22, reflection coefficient of multi-directional random waves is more than 0.4 maximally.

  • PDF

A Study about Establishment of Discrimination Model of Impact Factors of Big Traffic Accident -With Laws Violation Type- (대형교통사고 영향요인의 판별모델 구축에 관한 연구 -법규위반 유형을 중심으로-)

  • 오윤표;고상선
    • Journal of Korean Society of Transportation
    • /
    • v.10 no.3
    • /
    • pp.59-74
    • /
    • 1992
  • The change of industrial structure, the expansion of economic scale, the elevation of national life level and rapid motorization bring about social problems that are traffic accident, traffic congestion, etc. Especially, big traffic accidents bring about the great number of dead and wounded person with damage of property. But there are no study results available mainly focused on the big traffic accident analysis. Accordingly, this study is essentially for the factor analysis of big accident types including laws violation and the assaulting driver's death using Quantification ll method.

  • PDF

Technology Trends for Green Aviation Noise Reduction (친환경 항공을 위한 소음 저감 기술 동향)

  • Wie, Seong Yong;Hwang, Changjeon;Chung, Ki Hoon;Ahn, Ohsung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2013.10a
    • /
    • pp.241-246
    • /
    • 2013
  • The regulation of the aircraft noise has been more strengthened with expansion of the environmental issue. This trend has encouraged the R&D of the noise reduction technology. In this paper, the international efforts for aircraft noise reduction and the related technology were investigated. The aircraft noise sources were also introduced briefly. Additionally, the noise prediction method was explained at the end of paper.

  • PDF

The NMR Pseudocontact Shift of Tetrahedral and Pseudo-Tetrahedral Complex of Cu(II)

  • Kim, Dong Hui;Lee, Gi Hak
    • Bulletin of the Korean Chemical Society
    • /
    • v.17 no.1
    • /
    • pp.69-72
    • /
    • 1996
  • The NMR dipolar shift in tetrahedral and tetragonally-distorted tetrahedral complexes for Cu(Ⅱ) has been calculated adopting nonmultipole expansion method. The exact solution of ΔB/B(ppm) is exactly in agreement with multipolar results when R, the distance between the paramagnetic ion and the nucleus, is larger than 0.2 nm. The major contribution to the dipolar shift arises from 1/R3 term but the other terms, 1/R5 and 1/R7, contribute significantly to the pseudocontact shift when R is shorter than 0.5 nm. The shift is mainly due to the 3d orbitals and sensitive to distortion parameters at short range of R.

An Examination on the Singularoty of Grad Moment Equation for Shock Wave Problems

  • 오영기
    • Bulletin of the Korean Chemical Society
    • /
    • v.17 no.4
    • /
    • pp.385-390
    • /
    • 1996
  • It has been well known that the Grad thirteen-moment equations have solutions only when the Mach number is less than a limiting value for the stationary plane shock-waves. The limit of Mach number has been re-examined by including successive terms in the series expansion of distribution function. The method employed is the linear analysis of moment equations near up-streaming and down-streaming flows. For the thirteen moment case, it has been confirmed that equations have solutions only when the Mach number is less than 1.6503, which is consistent with the literature value. For the case of twenty moments, the limit of Mach number is decreased to 1.3416.

Effects of elastic foundation on the dynamic stability of cylindrical shells

  • Ng, T.Y.;Lam, K.Y.
    • Structural Engineering and Mechanics
    • /
    • v.8 no.2
    • /
    • pp.193-205
    • /
    • 1999
  • A formulation for the dynamic stability analysis of cylindrical shells resting on elastic foundations is presented. In this previously not studied problem, a normal-mode expansion of the partial differential equations of motion, which includes the effects of the foundation as well as a harmonic axial loading, yields a system of Mathieu-Hill equations the stability of which is analyzed using Bolotin's method. The present study examines the effects of the elastic foundation on the instability regions of the cylindrical shell for the transverse, longitudinal and circumferential modes.

ITS 평가요인의 모델구축에 관한 연구 ( A Study for Model Establishment of Evaluation Factor on the Intelligent Transportation System ( ITS ) )

    • Journal of Korean Port Research
    • /
    • v.12 no.1
    • /
    • pp.47-53
    • /
    • 1998
  • Presently, it was faced with serious social problems as traffic accident, parking violation & traffic congestion due to change of industrial structure, expansion of economic volume, elevation of national life level and rapid motorization. Accordingly, the study is research to improve immidiate transportation problems which could be establish the rating model about consideration degree of evaluation factor based on MDPREF's method in connection with Intelligent Transportation System(ITS)

  • PDF