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    List of Articles Mehdi Ghannad


  • Article

    1 - A thermoelasticity solution for thick cylinders subjected to thermo-mechanical loads under various boundary conditions
    International Journal of Advanced Design and Manufacturing Technology , Issue 5 , Year , Autumn 2015
    In this paper, a thermoelasticity solution for steady state response of thick cylinders which are subjected to pressure and external heat flux in inner surface is presented. Displacement field obeys the kinematics of the first order shear deformation theory (FSDT). It i More
    In this paper, a thermoelasticity solution for steady state response of thick cylinders which are subjected to pressure and external heat flux in inner surface is presented. Displacement field obeys the kinematics of the first order shear deformation theory (FSDT). It is assumed that the temperature varies both along the length and the thickness. The variation of the temperature occurs linearly through the thickness. Using energy method, the equilibrium equations and general boundary conditions are derived for the cylinder. Based on the developed analytical solution, adequate numerical results are depicted to provide an insight into the influence of the thermal and mechanical loads and boundary conditions on thermo-mechanical behavior of cylinder. Results show that shear stresses are noticeable at boundaries; moreover, temperature, displacement fields and stresses are strongly depended on length. Furthermore, the capability of the proposed method to solve any axisymmetrically cylindrical shells with general boundary conditions and thermo-mechanical loading is proven. Manuscript profile

  • Article

    2 - Creep Behavior of Cylinders Subjected to an Internal Pressure and a Two Dimensional Temperature Field Using First Order Shear Deformation Theory
    Journal of Solid Mechanics , Issue 4 , Year , Summer 2023
    In this paper, the creep analysis in a thick-walled cylinder subjected to internal pressure and heat flux at the inner and outer surfaces has been investigated. The displacement field is obtained based on the first-order shear deformation theory and the thermal field is More
    In this paper, the creep analysis in a thick-walled cylinder subjected to internal pressure and heat flux at the inner and outer surfaces has been investigated. The displacement field is obtained based on the first-order shear deformation theory and the thermal field is assumed two-dimensional through the thickness and along cylinder whose in radial direction the thermal field is considered linear. The equilibrium equations of the mechanical and thermal fields were derived using the energy method and the principle of virtual work for mechanical loading and heat flux. The creep behavior is described by Bailey-Norton’s time-dependent creep law. Analytical solutions with iteration methods have been used to obtain the stresses, strains, and displacement. The relationship between the temperature and the creep deformation was investigated by examining changes in the radial displacement by increasing the temperature by two to three times at a specific point. The effects of parameters such as pressure, heat flux and radial displacement at different temperatures on stress distribution were discussed. It was shown the circumferential stress accounts for the most changes caused by creep behavior. The presented method provides a semi-analytical solution to investigate the creep behavior of the thick-walled cylinders, which can be used for purposes such as designing and their optimization and parametric study under real temperature loading conditions. Manuscript profile

  • Article

    3 - Effect of Material Gradient on Stresses of FGM Rotating Thick-Walled Cylindrical Pressure Vessel with Longitudinal Variation of Properties under Non-uniform Internal and External Pressure
    Journal of Advanced Materials and Processing , Issue 2 , Year , Spring 2016
    The present paper provides a semi-analytical solution to obtain the displacements and stresses in a functionally graded material (FGM) rotating thick cylindrical shell with clamped ends under non-uniform pressure. Material properties of cylinder are assumed to change al More
    The present paper provides a semi-analytical solution to obtain the displacements and stresses in a functionally graded material (FGM) rotating thick cylindrical shell with clamped ends under non-uniform pressure. Material properties of cylinder are assumed to change along the axial direction according to a power law form. It is also assumed that the Poisson’s ratio is constant. Given the existence of shear stress in the thick cylindrical shell due to material and pressure changes along the axial direction, the governing equations are obtained based on first-order shear deformation theory (FSDT). These equations are in the form of a set of general differential equations with variable coefficients. Given that the FG cylinder is divided into n homogenous disks, n sets of differential equations with constant coefficients are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. The problem was also solved, using the finite element method (FEM), the results of which were compared with those of the multi-layered method (MLM). Finally, some numerical results are presented to study the effects of applied pressure, non-homogeneity index, and power law index of FGM on the mechanical behavior of the cylindrical shell. Manuscript profile