Dynamic instability of nanocomposite piezoelectric‐ leptadenia pyrotechnica rheological elastomer‐porous functionally graded materials micro viscoelastic beams at various strain gradient higher‐order theories

2021 ◽  
Author(s):  
M. S. H. Al‐Furjan ◽  
Y. Yang ◽  
Ahmad Farrokhian ◽  
X. Shen ◽  
Reza Kolahchi ◽  
...  
Keyword(s):  
Functionally Graded Materials ◽  
Strain Gradient ◽  
Dynamic Instability ◽  
Higher Order ◽  
Functionally Graded ◽  
Graded Materials

Nonlinear Pull-In Instability of Strain Gradient Microplates Made of Functionally Graded Materials

2019 ◽  
Vol 19 (02) ◽  
pp. 1950007 ◽  
Author(s):  
R. Gholami ◽  
R. Ansari ◽  
H. Rouhi
Keyword(s):  
Functionally Graded Materials ◽  
Strain Gradient ◽  
Scale Effects ◽  
Functionally Graded ◽  
Strain Gradient Theory ◽  
Small Scale ◽  
Gradient Theory ◽  
Graded Materials ◽  
First Order ◽  
Size Dependent

In this paper, the size-dependent nonlinear pull-in behavior of rectangular microplates made from functionally graded materials (FGMs) subjected to electrostatic actuation is numerically studied using a novel approach. The small scale effects are taken into account according to Mindlin’s first-order strain gradient theory (SGT). The plate model is formulated based on the first-order shear deformation theory (FSDT) using the virtual work principle. The size-dependent relations are derived in general form, which can be reduced to those based on different elasticity theories, including the modified strain gradient, modified couple stress and classical theories (MSGT, MCST and CT). The solution of the problem is arrived at by employing an efficient matrix-based method called the variational differential quadrature (VDQ). First, the quadratic form of the energy functional including the size effects is obtained. Then, it is discretized by the VDQ method using a set of matrix differential and integral operators. Finally, the achieved discretized nonlinear equations are solved by the pseudo arc-length continuation method. In the numerical results, the effects of material length scale parameters, side length-to-thickness ratio and FGM’s material gradient index on the nonlinear pull-in instability of microplates with different boundary conditions are investigated. A comparison is also made between the predictions by the MSGT, MCST and CT.

The Higher Order Crack-Tip Field for Reissner's Bidirectional FGMs Spherical Shell

2013 ◽  
Vol 748 ◽  
pp. 341-344
Author(s):  
Yao Dai ◽  
Zhang Lei ◽  
Xiao Chong
Keyword(s):  
Spherical Shell ◽  
Functionally Graded Materials ◽  
Superposition Principle ◽  
Crack Tip ◽  
Higher Order ◽  
Functionally Graded ◽  
Homogeneous Material ◽  
Crack Tip Field ◽  
Graded Materials ◽  
Crack Problems

The crack tip fields for a cracked functionally graded materials spherical shell considering Reissners effect are obtained. Similar to Williams solution for homogeneous material, the eigen-solution of the crack tip field for bi-directional FGMs spherical shell is obtained by stress superposition principle. This result can be used to deal with the crack problems for FGMs shell.

The Crack-Tip Higher Order Fields of Linear FGM Plates with Reissner’s Effect

2012 ◽  
Vol 476-478 ◽  
pp. 1421-1424
Author(s):  
Yao Dai ◽  
Jun Feng Liu ◽  
Lei Zhang ◽  
Xiao Chong
Keyword(s):  
Asymptotic Expansion ◽  
Functionally Graded Materials ◽  
Crack Tip ◽  
Expansion Method ◽  
Higher Order ◽  
Functionally Graded ◽  
Transverse Shear Deformation ◽  
Plate Bending ◽  
Graded Materials ◽  
Asymptotic Expansion Method

The Reissner’s plate bending theory with consideration of transverse shear deformation effects is adopted to study the fundamental fracture problem in functionally graded materials(FGMs) plates for a crack parallel to material gradient. By means of the asymptotic expansion method, the crack-tip higher order asymptotic fields which are similar to the famous Williams’ solutions to homogeneous materials are obtained.

scholarly journals An exponential-trigonometric higher order shear deformation theory (HSDT) for bending, free vibration, and buckling analysis of functionally graded materials (FGMs) plates

2020 ◽  
Vol 29 ◽  
pp. 096369351987573 ◽  
Author(s):  
Yamna Belkhodja ◽  
Djamel Ouinas ◽  
Fatima Zohra Zaoui ◽  
Hamida Fekirini
Keyword(s):  
Free Vibration ◽  
Shear Deformation ◽  
Functionally Graded Materials ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Higher Order ◽  
Functionally Graded ◽  
Shear Stresses ◽  
Graded Materials

Two assumptions have been made based on by this proposed theory, which come from recently developed exponential–trigonometric shape function for transverse shear deformation effect and a simple higher order shear deformation theory for plate, based on a constraint between two rotational displacements of axis parallel to the plate midplane, about the axes x, y Cartesian coordinates system, which caused fewer unknown number. For the application of this method, a displacement field extended as only bending membrane for transverse displacement is used, a governing equations of motion as a result are determined according to Hamilton’s principle, and simplified using Navier analytical solutions, as well as the transverse shear stresses effect that satisfied the stress-free boundary conditions on the simply supported plate free faces as a parabolic variation along the thickness are taken into account. A functionally graded materials plates are chosen for the parametric study, where the plates are functionally graded continuously in materials through the plate thickness as a function of power law or exponential form. The aim of this study is to analyze the bending, free vibration as well as the buckling mechanical behaviors, where the results are more focused on the investigation of different parameters such as the volume fraction index, geometric ratios, frequency modes, in-plane compressive load parameters and material properties effects on the deflection, stresses, natural frequencies, and critical buckling load, which are validated in terms of accuracy and efficiency with other plate theories results found in the literature.

Higher Order Crack-Tip Fields of Reissner’s Linear Functionally Graded Materials Plates

2012 ◽  
Vol 549 ◽  
pp. 914-917
Author(s):  
Yao Dai ◽  
Jun Feng Liu ◽  
Lei Zhang ◽  
Xiao Chong ◽  
Hong Qian Chen
Keyword(s):  
Functionally Graded Materials ◽  
Crack Problem ◽  
Crack Tip ◽  
Expansion Method ◽  
Higher Order ◽  
Functionally Graded ◽  
Graded Materials ◽  
Fracture Theory ◽  
Bending Fracture ◽  
Asymptotic Expansion Method

Reissner’s plate bending fracture theory with consideration of transverse shear deformation effects is adopted for the crack problem of functionally graded materials (FGMs) plates. Assume that the crack is perpendicular to the material property gradient. By applying the asymptotic expansion method, the crack-tip higher order asymptotic fields which are similar to Williams’ solutions of homogeneous materials are obtained.

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