The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform

Alexander Bajenitchev - One of the best experts on this subject based on the ideXlab platform.

  • a numerical procedure for a non Linear Elastic Problem for incompressible material based on a perturbation method
    Computer Methods in Applied Mechanics and Engineering, 1996
    Co-Authors: Alexander Bajenitchev
    Abstract:

    Abstract A new approach for obtaining numerical solution of a non-Linear Elastic Problem for incompressible material is discussed. Finite element approximations for displacements and hydrostatic stresses (Lagrangian multiplier) are independent. A method of step-by-step loading is applied. A non-Linear Problem is solved in each step. Newton-Raphson approximations are supplemented with closer definition of a perturbation method by carrying out a limited number of iterations. A special method for solving the set of Linear algebraic equations with a large number of sparse constraints is described. New results about the behaviour of force-displacement dependence for the Problem examined by Klingbeil and Shield obtained by its numerical solution are presented.

K. Naumenko - One of the best experts on this subject based on the ideXlab platform.

  • Steady-state creep analysis of pressurized pipe weldments by perturbation method
    International Journal of Solids and Structures, 2006
    Co-Authors: A.v. Shutov, H. Altenbach, K. Naumenko
    Abstract:

    AbstractThe stress analysis of pressurized circumferential pipe weldments under steady state creep is considered. The creep response of the material is governed by Norton’s law. Numerical and analytical solutions are obtained by means of perturbation method, the unperturbed solution corresponds to the stress field in a homogeneous pipe. The correction terms are treated as stresses defined with the help of an auxiliary Linear Elastic Problem. Exact expressions for jumps of hoop and radial stresses at the interface are obtained. The proposed technique essentially simplifies parametric analysis of multi-material components

Gianni Royer-carfagni - One of the best experts on this subject based on the ideXlab platform.

  • Membrane analogy for multi-material bars under torsion.
    Proceedings. Mathematical physical and engineering sciences, 2019
    Co-Authors: Laura Galuppi, Gianni Royer-carfagni
    Abstract:

    Prandtl's membrane analogy for the torsion Problem of prismatic homogeneous bars is extended to multi-material cross sections. The Linear Elastic Problem is governed by the same equations describing the deformation of an inflated membrane, differently tensioned in regions that correspond to the domains hosting different materials in the bar cross section, in a way proportional to the inverse of the material shear modulus. Multi-connected cross sections correspond to materials with vanishing stiffness inside the holes, implying infinite tension in the corresponding portions of the membrane. To define the interface constrains that allow to apply such a state of prestress to the membrane, a physical apparatus is proposed, which can be numerically modelled with a two-dimensional mesh implementable in commercial finite-element model codes. This approach presents noteworthy advantages with respect to the three-dimensional modelling of the twisted bar.

Graziano Leoni - One of the best experts on this subject based on the ideXlab platform.

  • Numerical analysis of thin walled beams with internal unbonded cables by the Ritz method
    International Journal of Solids and Structures, 1998
    Co-Authors: Andrea Dall'asta, Graziano Leoni
    Abstract:

    The authors analyze the behavior of thin walled beams crossed by internal stretched cables anchored at their ends but free to slip without friction along their path, by using a previously presented model. The guidelines for the numerical solution of the Linear Elastic Problem and the stability analysis are presented in general form and applied to a class of Problems of technical interest. The numerical analysis examines the case of simply supported beam with symmetric open cross section, crossed by a cable placed on rectiLinear or parabolic paths lying in the symmetry plane, assuming as Problem variables the beam stiffness, the parameters describing the cable path and the cable traction force. This permitted evidencing some aspects of the Problem of interest in structural engineering, by showing the relations between stress increments of beam and cable under external force and the complex relations arising between beam bending, torsional and shear stiffness, cable path, cable traction force and external load in the stability analysis.

Shimin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Correspondence Relation Between Linear Elastic Problem and Newtonian Fluid Problem
    Chinese Journal of Geophysics, 2000
    Co-Authors: Shimin Wang, Ren Wang
    Abstract:

    The correspondence relation between a Linear Elastic Problem and a Newtonian fluid Problem is discussed in the paper. It is shown that, to establish the correspondence relation between the two Problems, it is not enough to consider the constitutive equations only. On the basis of a comparison of all basic equations between the two Problems, it is proved that a Newtonian fluid Problem satisfying the three conditions of (1)incompressible; (2)small Reynolds number; (3) temperature-independent viscosity, is equivalent to a quasi-static incompressible Linear Elastic Problem. Applying this equivalence relation to the numerical simulation of the tectonic stress field, the computer programs for Elastic Problems can be used to solve the viscous flow of the lithosphere.

  • CORRESPONDENCE BETWEEN Linear Elastic Problem AND NEWTONIAN FLUID Problem
    Chinese Journal of Geophysics, 2000
    Co-Authors: Shimin Wang
    Abstract:

    The correspondence between a Linear Elastic Problem and a Newtonianfluid Problem is discussed in the paper. It is shown that to establish thecorrespondence between the two Problems, it is not enough to consider theconstitutive equations only. On the basis of a comparison of all basic equations of thetwo Problems, it is proved that a Newtonian fluid Problem, which satisfy threeconditions: (1) incompressible; (2) small Reynolds number; (3) temperatureindependent viscosity, is equivalent to a quasi-static incompressible Linear ElasticProblem. Applying this equlvalence to the numerical simulation of the tectonic stressfield, the computer programs for Elastic Problems can be used to solve the viscousflow of the lithosphere.