• 제목/요약/키워드: Half space

검색결과 789건 처리시간 0.027초

SH-wave propagation in a heterogeneous layer over an inhomogeneous isotropic elastic half-space

  • Kakar, Rajneesh
    • Earthquakes and Structures
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    • 제9권2호
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    • pp.305-320
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    • 2015
  • The present paper is devoted to study SH-wave propagation in heterogeneous layer laying over an inhomogeneous isotropic elastic half-space. The dispersion relation for propagation of said waves is derived with Green's function method and Fourier transform. As a special case when the upper layer and lower half-space are homogeneous, our derived equation is in agreement with the general equation of Love wave. Numerically, it is observed that the velocity of SH-wave increases with the increase of inhomogeneity parameter.

Effect of fractional order on energy ratios at the boundary surface of elastic-piezothermoelastic media

  • Kumar, Rajneesh;Sharma, Poonam
    • Coupled systems mechanics
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    • 제6권2호
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    • pp.157-174
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    • 2017
  • In the present investigation reflection and transmission of plane waves at an elastic half space and piezothermoelastic solid half space with fractional order derivative is discussed. The piezothermoelastic solid half space is assumed to have 6 mm type symmetry and assumed to be loaded with an elastic half space. It is found that the amplitude ratios of various reflected and refracted waves are functions of angle of incidence, frequency of incident wave and are influenced by the piezothermoelastic properties of media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios are computed numerically using amplitude ratios for a particular model of graphite and Cadmium Selenide (CdSe). The variations of energy ratios with angle of incidence are shown graphically. The conservation of energy across the interface is verified. Some cases of interest are also deduced from the present investigation.

직교이방성 층과 반무한체 사이의 계면균열에 대한 좌굴 (Buckling for an Interface Crack Between an Orthotropic Layer and a Half-Space)

  • 정경문;범현규
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.815-818
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    • 2001
  • The buckling of an orthotropic layer bonded to an isotropic half-space with an interface crack subjected to compressive load under plane strain is considered. Basic stability equations derived from the mathematical theory of elasticity are applied to describe the buckling behavior. A system of homogeneous Cauchy-type singular integral equations of the second kind is solved numerically by utilizing Gauss-Chebyshev integral formulae. Numerical results for the buckling load are presented for various delamination geometries and material properties of both the layer and half-space.

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3차원 다층 반무한상 구조물의 동적 간섭에 관한 해석적 연구 (Three Dimensional Dynamic Interaction of Foundations on Layered Half-Space)

  • 조우연;이강원;임윤묵;김문겸
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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    • pp.75-82
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    • 2001
  • A dynamic interaction analysis of an adjacent surface fecundation on a layered half-space is performed in the frequency domain. A semi-analytical approach is employed to reduce the integration range of the wavenumber in the surface fundamental solution for a layered half-space in boundary element (BE) formulations. The present study then adopts a combined boundary and finite element method to analyze the dynamic behavior of a system of flexible surface foundations on an elastic homogeneous and layered half-space. Numerical examples are presented to demonstrate the accuracy of the developed method. The examples show the feasibility of an extended application fur the complicated dynamic interaction of foundations on layered media.

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손실 반공간에 묻힌 원통형 산란체의 검출 및 영상제구성에 의한 식별 (Iterative Teconstruction of a Cylinder Buried in the Lossy Half Space)

  • 김정석;나정웅
    • 한국전자파학회논문지
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    • 제11권6호
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    • pp.939-945
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    • 2000
  • 손실 반공간 묻혀 원동형 산란체와 주면 매질의 특성을 반복 기법 최적화 역산란을 적용하여 구했다. 산란파는 경계요소법을 이용하여 계산하였으며 산란체의 크기, 위치 내부매질의 비유전율, 도전율, 주변 매질의 비유전율, 도전율 등의 파라미터는 측정 산란파로부터 유전 알고리즘과 Levenberg-Marquardt 알고리즘의 혼합 알고리즘을 이요하여 역으로 계산하였다. 산란타의 측정오차에 의한 illposedness는 파수 영역에서 자수함수적으로 감쇠하는 감쇠모드를 제거하여 안정하시켰다.

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판과 지반의 분리를 고려한 반무한 탄성지반상에 놓인 사각형 평판의 접촉응력 해석 (The Analysis of Contact Pressure of Plate on Elastic Half-Space Considering Local Separation between Plate and Half-Space)

  • 조현영;정진환;김성철;김호진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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    • pp.73-79
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    • 1997
  • It is one of classical problems in the elastic theory to analyze contact stresses between elastic bodies. Concrete pavements under traffic wheel loads can be considered as one of these typical Problems. In the paper, Mindlin plate theory is used to consider the transverse shear effect, 8-node isoparametric plate bending element is adopted in this study, and an elastic plate resting on tensionless elastic half-space is analyzed by finite element method. The Boussineq's solution of elastic half-space is used to evaluate the flexibility of foundation. To obtain the boundary of contact area, the flexibility matrix of foundation is modified after each cycle of analysis iteratively. A Numerical example is presented by using these method.

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초기치를 갖는 비동질무한영역의 해석을 위한 비례경계무한요소법 (Infinite element for the scaled boundary analysis of initial valued non-homogeneous elastic half space)

  • 이계희
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.259-264
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    • 2007
  • In this paper, to analyze the initial valued non-homogeneous elastic half space by the scaled boundary analysis, the infinite element approach was introduced. The free surface of the initial valued non-homogeneous elastic half space was mode1ed as a circumferential direction of boundary scaled boundary coordinate. The infinite element was used to represent the infinite length of the free surface. The initial value of material property(elastic modulus) was considered by the combination of the position of the sealing center and the power function of the radial direction. By use of the mapping type infinite element, the consistent e1ements formulation could be available. The performance and the feasibility of proposed approach are examined by two numerical examples.

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EINSTEIN HALF LIGHTLIKE SUBMANIFOLDS WITH SPECIAL CONFORMALITIES

  • Jin, Dae Ho
    • 대한수학회보
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    • 제49권6호
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    • pp.1163-1178
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    • 2012
  • In this paper, we study the geometry of Einstein half lightlike submanifolds M of a semi-Riemannian space form $\bar{M}(c)$ subject to the conditions: (a) M is screen conformal, and (b) the coscreen distribution of M is a conformal Killing one. The main result is a classification theorem for screen conformal Einstein half lightlike submanifolds of a Lorentzian space form with a conformal Killing coscreen distribution.

NON-EXISTENCE FOR SCREEN QUASI-CONFORMAL IRROTATIONAL HALF LIGHTLIKE SUBMANIFOLDS OF A SEMI-RIEMANNIAN SPACE FORM ADMITTING A SEMI-SYMMETRIC NON-METRIC CONNECTION

  • Jin, Dae Ho
    • East Asian mathematical journal
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    • 제31권3호
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    • pp.337-344
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    • 2015
  • We study screen quasi-conformal irrotational half lightlike submanifolds M of a semi-Riemannian space form $\bar{M}$ (c) equipped with a semi-symmetric non-metric connection subject such that the structure vector field of $\bar{M}$ (c) belongs to the screen distribution S(TM). The main result is a non-existence theorem for such half lightlike submanifolds.