The Experts below are selected from a list of 14172 Experts worldwide ranked by ideXlab platform

Sami Elborgi - One of the best experts on this subject based on the ideXlab platform.

  • a double receding contact Axisymmetric Problem between a functionally graded layer and a homogeneous substrate
    Mechanics of Materials, 2011
    Co-Authors: Moez Rhimi, Sami Elborgi, Nizar Lajnef
    Abstract:

    Abstract In this paper, the Axisymmetric Problem of a frictionless double receding contact between a rigid stamp of Axisymmetric profile, an elastic functionally graded layer and a homogeneous half space is considered. The graded layer is modelled as a nonhomogeneous medium with an isotropic stress-strain law. Assuming the double contact between the bodies to be frictionless, only compressive normal tractions can be transmitted in each contact area while the rest of the surface is free of tractions. Using an appropriate integral transform, the Axisymmetric elasticity equations are converted analytically into a system of singular integral equations where the unknowns are the pressures and the radii of the receding contact area in the two contact zones. The global equilibrium conditions are supplemented to solve the Problem. The singular integral equations are solved numerically using orthogonal Chebyshev polynomials. An iterative scheme based on the Newton–Raphson method is employed to obtain the receding contact radii and pressures that satisfy the equilibrium conditions. The main objectives of the paper are to study the effect of the nonhomogeneity parameter, the thickness of the graded layer and the magnitude of the applied load on the contact pressures, the radii of the receding contact zones and the indentation for the case of a spherical rigid punch.

  • an Axisymmetric Problem of an embedded crack in a graded layer bonded to a homogeneous half space
    International Journal of Solids and Structures, 2010
    Co-Authors: M. Rekik, M Neifar, Sami Elborgi
    Abstract:

    In an attempt to simulate non-uniform coating delamination, the elasto-static Problem of a penny shaped Axisymmetric crack embedded in a functionally graded coating bonded to a homogeneous substrate subjected to crack surface tractions is considered. The coating’s material gradient is parallel to the Axisymmetric direction and is orthogonal to the crack plane. The graded coating is modeled as a non-homogeneous medium with an isotropic constitutive law. Using Hankel transform, the governing equations are converted into coupled singular integral equations, which are solved numerically to yield the crack tip stress intensity factors. The Finite Element Method was additionally used to model the crack Problem. The main objective of this paper is to study the influence of the material non-homogeneity and the crack position on the stress intensity factors for the purpose of gaining better understanding on the behavior of graded coatings.

M J Simon - One of the best experts on this subject based on the ideXlab platform.

  • a note on uniqueness in the linearized water wave Problem
    Journal of Fluid Mechanics, 1999
    Co-Authors: N G Kuznetsov, M J Simon
    Abstract:

    The uniqueness theorem of Simon & Ursell, concerning the linearized two-dimensional water-wave Problem in a fluid of infinite depth, is extended in two directions. First, we consider a two-dimensional geometry involving two submerged symmetric bodies placed sufficiently far apart that they are not confined in the vertical right angle having its vertex on the free surface as the theorem of Simon & Ursell requires. A condition is obtained guaranteeing the uniqueness outside a finite number of bounded frequency intervals. Secondly, the method of Simon & Ursell is generalized to prove uniqueness in the Axisymmetric Problem for bodies violating John's condition provided the free surface is a connected plane region

Ya G Popov - One of the best experts on this subject based on the ideXlab platform.

  • Axisymmetric Problem of stressed state for a twice truncated cone
    Journal of Mathematical Sciences, 2014
    Co-Authors: N D Vaisfeld, Ya G Popov, A V Reut
    Abstract:

    We consider an Axisymmetric mixed Problem of stressed state for a twice-truncated cone with regard for its own weight and the conditions of smooth contact imposed on its conical surface. The application of a new integral transformation with respect to the meridian angle directly to the Lame equations reduces the Problem in the space oftransforms to a one-dimensional vector boundary-value Problem. The obtained Problem is solved exactly with the help of the methods of matrix differential calculus. The subsequent application of the inverse integral transformations gives the final solution of the original Problem. We study the solutions in special cases of the formulated Problem, such as a cone with spike, a spherical dome, and a half ball. We also determine the normal stresses acting on the surface of the cone depending on its geometric parameters.

  • the non Axisymmetric Problem of the stress concentration in an unbounded elastic medium near a spherical slit
    Journal of Applied Mathematics and Mechanics, 1992
    Co-Authors: Ya G Popov
    Abstract:

    Abstract Using the approach described in [1], the non-Axisymmetric Problem of the stress concentration in an unbounded elastic medium near a spherical slit is reduced to three, one-dimensional, separately solvable, integral equations. Their exact solution is obtained in a class of functions with non-integrable singularities and is used, as in [1], to derive simple formulae for the stress intensity factors. The Axisymmetric modification of this Problem has been investigated in [2–5].

Federico J. Sabina - One of the best experts on this subject based on the ideXlab platform.

  • Small-scale indentation of an elastic coated half-space: The effect of compliant substrate
    International Journal of Engineering Science, 2016
    Co-Authors: Ivan Argatov, Federico J. Sabina
    Abstract:

    Abstract Under consideration in this paper is the Axisymmetric Problem of unilateral frictionless indentation of a thin stiff film bonded to a compliant substrate, which is assumed to be a homogeneous isotropic elastic half-space. The previously developed first-order asymptotic model for the small-scale indentation, when the contact radius is small compared to the film thickness, is compared with approximate solutions based on the Kirchhoff thin plate theory with satisfactory results.

Yoshihiro Ochiai - One of the best experts on this subject based on the ideXlab platform.

  • Axisymmetric thermal stress analysis in the steady state with heat generation in the region by boundary element method
    Journal of Thermal Stresses, 1996
    Co-Authors: Yoshihiro Ochiai, Tsuyoshi Sekiya
    Abstract:

    The boundary element method (BEM) does not require a domain integral in steady thermoelastic Problems without heat generation. However, in Problems with heat generation, the domain integral is necessary. This article shows that the Axisymmetric Problem of steady thermoelasticity with nonuniform heat generation over the region can be easily solved without a domain integral by means of BEM. This method can also be applied to steady thermal stress Problems under complicated general heat generation. However, for general heat generation the domain must be divided into small areas in which distributions of the heat generation approximately satisfy the Laplace equation.

  • Axisymmetric thermal stress analysis in the steady state with heat generation in the region by boundary element method
    Transactions of the Japan Society of Mechanical Engineers. A, 1993
    Co-Authors: Yoshihiro Ochiai
    Abstract:

    The boundary element method (BEM) does not require a domain integral in steady thermoelastic Problems without heat generation. However, in Problems with heat generation, the domain integral is necessary. This paper shows that the Axisymmetric Problem of steady thermoelasticity with nonuniform heat generation over the region can be easily solved without a domain integral by means of BEM. This method can also be applied to steady thermal stress Problems under complicated general heat generation. However, for general heat generation the domain must be divided into small areas, in which distributions of heat generation approximately satisfy the Laplace equation.