scholarly journals Thermal Residual Stresses Analyses of Two-Dimensional Functionally Graded Circular Plates with Temperature-Dependent Material Properties

2018 ◽  
pp. 202-213
Author(s):  
Munise Didem DEMİRBAŞ ◽  
Mustafa Kemal APALAK
Keyword(s):  
Residual Stresses ◽  
Material Properties ◽  
Functionally Graded ◽  
Two Dimensional ◽  
Circular Plates ◽  
Temperature Dependent ◽  
Thermal Residual Stresses

In-Plane Thermal Residual Stresses in Functionally Graded Plates

2014 ◽  
Author(s):  
M. Kemal Apalak ◽  
M. Didem Demirbas
Keyword(s):  
Residual Stresses ◽  
Linear Equations ◽  
Plate Thickness ◽  
Transient Heat Conduction ◽  
Functionally Graded ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Functionally Graded Plates ◽  
Compositional Gradient ◽  
Thermal Residual Stresses

This study addresses in-plane thermal residual stresses in two-dimensional functionally graded plates under a constant in-plane heat flux. The plate material properties vary with a power law along two in-plane directions not through the plate thickness. The transient heat conduction and Elasticity’s Navier equations describing the two-dimensional thermo-elastic problem were discretized using the finite-difference method, and the set of linear equations was solved using the pseudo singular value method. The in-plane transient distributions of temperature, displacement, stress and strain components were determined, and the two-dimensional exponents and directions of compositional gradient were investigated in terms of their effects on the stress and strain distributions in both plates. The exponent and direction of the compositional gradient affected the peak in-plane strain and stress levels; therefore, the stress and strain distributions can be relieved by arranging the exponent and directions of the compositional gradient.

Designing Optimal Volume Fractions For Functionally Graded Materials With Temperature-Dependent Material Properties

2006 ◽  
Vol 74 (5) ◽  
pp. 861-874 ◽  
Author(s):  
Florin Bobaru
Keyword(s):  
Functionally Graded Materials ◽  
Material Properties ◽  
Volume Fraction ◽  
Effective Properties ◽  
Functionally Graded ◽  
Dominant Factor ◽  
Temperature Dependent ◽  
Graded Materials ◽  
Critical Stresses ◽  
Non Linear

We present a numerical approach for material optimization of metal-ceramic functionally graded materials (FGMs) with temperature-dependent material properties. We solve the non-linear heterogeneous thermoelasticity equations in 2D under plane strain conditions and consider examples in which the material composition varies along the radial direction of a hollow cylinder under thermomechanical loading. A space of shape-preserving splines is used to search for the optimal volume fraction function which minimizes stresses or minimizes mass under stress constraints. The control points (design variables) that define the volume fraction spline function are independent of the grid used in the numerical solution of the thermoelastic problem. We introduce new temperature-dependent objective functions and constraints. The rule of mixture and the modified Mori-Tanaka with the fuzzy inference scheme are used to compute effective properties for the material mixtures. The different micromechanics models lead to optimal solutions that are similar qualitatively. To compute the temperature-dependent critical stresses for the mixture, we use, for lack of experimental data, the rule-of-mixture. When a scalar stress measure is minimized, we obtain optimal volume fraction functions that feature multiple graded regions alternating with non-graded layers, or even non-monotonic profiles. The dominant factor for the existence of such local minimizers is the non-linear dependence of the critical stresses of the ceramic component on temperature. These results show that, in certain cases, using power-law type functions to represent the material gradation in FGMs is too restrictive.

Geometrically nonlinear dynamic response and vibration of shear deformable eccentrically stiffened functionally graded material cylindrical panels subjected to thermal, mechanical, and blast loads

2018 ◽  
Vol 22 (3) ◽  
pp. 658-688 ◽  
Author(s):  
Nguyen Dinh Duc ◽  
Ngo Duc Tuan ◽  
Pham Hong Cong ◽  
Ngo Dinh Dat ◽  
Nguyen Dinh Khoa
Keyword(s):  
Dynamic Response ◽  
Functionally Graded Material ◽  
Material Properties ◽  
Nonlinear Dynamic ◽  
Functionally Graded ◽  
Blast Loads ◽  
Temperature Dependent ◽  
Nonlinear Dynamic Response ◽  
Cylindrical Panels ◽  
Graded Material

Based on the first order shear deformation shell theory, this paper presents an analysis of the nonlinear dynamic response and vibration of imperfect eccentrically stiffened functionally graded material (ES-FGM) cylindrical panels subjected to mechanical, thermal, and blast loads resting on elastic foundations. The material properties are assumed to be temperature-dependent and graded in the thickness direction according to simple power-law distribution in terms of the volume fractions of the constituents. Both functionally graded material cylindrical panels and stiffeners having temperature-dependent properties are deformed under temperature, simultaneously. Numerical results for the dynamic response of the imperfect ES-FGM cylindrical panels with two cases of boundary conditions are obtained by the Galerkin method and fourth-order Runge–Kutta method. The results show the effects of geometrical parameters, material properties, imperfections, mechanical and blast loads, temperature, elastic foundations and boundary conditions on the nonlinear dynamic response of the imperfect ES-FGM cylindrical panels. The obtained numerical results are validated by comparing with other results reported in the open literature.

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