• Title, Summary, Keyword: Inhomogeneous

Search Result 623, Processing Time 0.105 seconds

Dispersion of axisymmetric longitudinal waves in a "hollow cylinder + surrounding medium" system with inhomogeneous initial stresses

  • Akbarov, Surkay D.;Bagirov, Emin T.
    • Structural Engineering and Mechanics
    • /
    • v.72 no.5
    • /
    • pp.597-615
    • /
    • 2019
  • The paper studies the dispersion of the axisymmetric longitudinal wave propagating in the "hollow cylinder + surrounding medium" system with inhomogeneous initial stresses caused by the uniformly distributed radial compressional forces acting at infinity. Up to now in the world literature, there exist only a few investigations related to the wave dispersion in a hollow cylinder with inhomogeneous initial stresses. Therefore, this paper is one of the first attempts in this field in the sense of the development of investigations for the case where the cylinder is surrounded with an infinite medium. The three-dimensional linearized theory of elastic waves is used for describing the considered wave propagation problem and, for a solution to the corresponding mathematical problem, the discrete-analytical solution method is developed and employed. The corresponding dispersion equation is obtained and this equation is solved numerically and, as a result of this solution, the dispersion curves are constructed for the first and second modes. By analyzing these curves, the character of the influence of the inhomogeneous initial stresses on the dispersion curves is established. In particular, it is established that as a result of the inhomogeneity of the initial stresses both new dispersion curves and the "band gap" for the wave frequencies can appear.

ON THE ORBITAL STABILITY OF INHOMOGENEOUS NONLINEAR SCHRÖDINGER EQUATIONS WITH SINGULAR POTENTIAL

  • Cho, Yonggeun;Lee, Misung
    • Bulletin of the Korean Mathematical Society
    • /
    • v.56 no.6
    • /
    • pp.1601-1615
    • /
    • 2019
  • We show the existence of ground state and orbital stability of standing waves of nonlinear $Schr{\ddot{o}}dinger$ equations with singular linear potential and essentially mass-subcritical power type nonlinearity. For this purpose we establish the existence of ground state in $H^1$. We do not assume symmetry or monotonicity. We also consider local and global well-posedness of Strichartz solutions of energy-subcritical equations. We improve the range of inhomogeneous coefficient in [5, 12] slightly in 3 dimensions.

Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation (비균질 Pasternak 지반위에 얹혀진 박판의 자유진동 해석)

  • Kim, Il-Jung;Lee, Young-Soo;Oh, Soog-Kyoung;Lee, Hoy-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.395.2-395
    • /
    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considerded as concentrated masses on plate supported on foundation. In this paper. vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. (omitted)

  • PDF

Thickness Assessment of Adhesive Layer in Inhomogeneous Layer by Guided Wave (유도초음파에 의한 비균질 적층의 접합층두께 평가)

  • Cho, Youn-Ho;Ham, Hyo-Sik;Choi, Heung-Ho
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.21 no.4
    • /
    • pp.391-397
    • /
    • 2001
  • The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

  • PDF

Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation (비균질 Pasternak 지반 위에 놓인 박판의 자유진동 해석)

  • Lee, Yong-Soo;Oh, Soog-Kyoung;Lee, Hoy-Jin;Kim, Il-Jung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.982-987
    • /
    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considered as plate supported on foundation with concentrated masses. In this paper, vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. The solution of this paper are compared with existing solution and natural frequencies of thin plates, with concented mass, on inhomogeneous Pasternak foundation are calculated

  • PDF

Buckling and Vibration Analysis of Thick Plates with Concentrated Mass (집중 질량을 갖는 후판의 좌굴 및 진동해석)

  • 김일중;오숙경;이용수
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.467-474
    • /
    • 2001
  • This paper is for the buckling and vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. A thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analyize plate which is supported on inhomogeneous pasternak foundation, the value of winkler foundation parameter(WFP) of centural and border zone of plate are chosen as Kwl and Kw2 respectively. The value of Kwl and Kw2 can be changed as 0, 10, 10 /sup 2/, 10 / sup 3/ and the value of SFP(shear foundation parameter) also be changed 0, 5, 10, 15 respectively. Finally, In this paper, buckling stress of rectangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with or without uniform in-plane axial stresses are calculated

  • PDF

A ray-based approach to scattering from inhomogeneous dielectric objects (전파경로 투적에 의한 비균질 유전체의 전자파 산란)

  • Kim, Hyeongdong
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.32A no.2
    • /
    • pp.31-37
    • /
    • 1995
  • A ray-based approach is developed to calculate the scattering from inhomogeneous dielectric objects. This approach is a natural extension of the "shooting and bouncing ray(SBR)" technique developed earlier for calculating the radar cross section of cavity structures and complex targets. In this formulation, a dense grid of rays representing the incident field is shot toward the scatterer. The curved trajectory, amplitude, phase and polarization of the ray fields inside the inhomogeneous object are computed numerically based on the laws of geometrical optics. The contributions of the exting rays to the exterior scattered field are then calculated by using the equivalence principle in conjunction with " a ray-tube integration" scheme. The ray-based approach is applied for the effect of an arcjet plasma plume on satellite reflector performance and backscattering from inhomogeneous objects.

  • PDF

Anaysis and design of inhomogeneous optical filters using tapered transmission line theory (테이퍼 전송선 원리를 이용한 불균일 굴절률 광여파기의 해석 및 설계)

  • 권영재;장호성;임성규;오명환
    • Journal of the Korean Institute of Telematics and Electronics D
    • /
    • v.34D no.9
    • /
    • pp.36-42
    • /
    • 1997
  • Optical filters with graded index profiles are designed by applying the fourier transform to a riccati equation which governs the reflection and transmission characteristics of inhomogeneous refractive index distributions. The inhomogeneous refractive index profile of an optical filter with specified target spectrum is obtained through iterations. The spectra response of the inhomogeneous refractive index layers are analyzed by using runge-dutta numerical method to solve the differential euations of the amplitude and the phase of reflection coefficient derived from the riccati equation and the results are in good agreement with the resutls obtained by using matrix method.

  • PDF

Stability Analysis of Rectangular Plate with Concentrated Mass (집중질량을 갖는 장방형판의 안정해석)

  • 김일중;오숙경;이용수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.805-809
    • /
    • 2004
  • This paper is for the vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. The vibration of rectangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with Concentrated Mass are calculated A thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analysis plate which is supported on inhomogeneous pasternak foundation, the value of winkler foundation parameter(WFP) of centural and border zone of plate are chosen as WFP1 and WFP2 respectively. The value of WFP1 and WFP2 can be changed as 10, 10$^3$ and the value of SFP(shear foundation parameter) also be changed 5, 15 respectively.

  • PDF

Vibration Analysis of Rectangular Thick Hate with Concentrated Mass (집중질량을 갖는 후판의 진동해석)

  • Kim, Il-Jung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.711-714
    • /
    • 2005
  • This paper is for the vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. the thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analyize plat which is supported on inhomogeneous pasternak foundation, the value of winkler foundation parameter(WFP) of centural and border zone of plate are chosen as Kw1 and Kw2 respectively. The value of Kw1 and Kw2 can be changed as 0, 10, $10^2,\;10^3$ and the value of SFP(shear foundation parameter) also be changed 0, 5, 10, 15 respectively. Finally, In this paper, vibration of retangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with Concentrated Mass are calculated

  • PDF