Effect of Transverse Shear on Deformation of Thick Laminated Sandwich Plates

2006 ◽  
Vol 324-325 ◽  
pp. 279-282
Author(s):  
K. Gordnian ◽  
H. Hadavinia ◽  
J. Karwatzki
Keyword(s):  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Sandwich Plates ◽  
Maximum Deflection ◽  
Transverse Shear Stress ◽  
Cylindrical Bending ◽  
Element Analysis ◽  
Geometrical Properties ◽  
First Order

The effect of transverse shear on the deformation of thick laminated sandwich plates under cylindrical bending is studied, based on the first order shear deformation theory (FSDT) with the application of shear correction factor (SCF). It is shown that depending on the mechanical and geometrical properties of the layers, the contribution of the transverse shear stress to the maximum deflection of the plate is variable and in some cases accounts for up to around 88% of the total deflection. The analytical results are compared and verified with finite element analysis.

scholarly journals Vibration and buckling analysis of functionally graded sandwich plates with improved transverse shear stiffness based on the first-order shear deformation theory

2013 ◽  
Vol 228 (12) ◽  
pp. 2110-2131 ◽  
Author(s):  
Trung-Kien Nguyen ◽  
Thuc P Vo ◽  
Huu-Tai Thai
Keyword(s):  
Boundary Conditions ◽  
Power Law ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Shear Stiffness ◽  
Functionally Graded ◽  
Sandwich Plates ◽  
Simply Supported ◽  
First Order

An improved transverse shear stiffness for vibration and buckling analysis of functionally graded sandwich plates based on the first-order shear deformation theory is proposed in this paper. The transverse shear stress obtained from the in-plane stress and equilibrium equation allows to analytically derive an improved transverse shear stiffness and associated shear correction factor of the functionally graded sandwich plate. Sandwich plates with functionally graded faces and both homogeneous hardcore and softcore are considered. The material property is assumed to be isotropic at each point and vary through the plate thickness according to a power-law distribution of the volume fraction of the constituents. Equations of motion and boundary conditions are derived from Hamilton’s principle. The Navier-type solutions are obtained for simply supported boundary conditions, and exact formulae are proposed and compared with the existing solutions to verify the validity of the developed model. Numerical results are obtained for simply supported functionally graded sandwich plates made of three sets of material combinations of metal and ceramic, Al/Al2O3, Al/SiC and Al/WC to investigate the effects of the power-law index, thickness ratio of layer, material contrast on the shear correction factors, natural frequencies and critical buckling loads as well as load–frequency curves.

scholarly journals Static Analysis of Laminated Composite Plate Using First Order Shear Deformation Theory

2021 ◽  
Vol 9 (9) ◽  
pp. 1193-1210
Keyword(s):  
Shear Deformation ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Laminated Plate ◽  
Transverse Shear Stress ◽  
Laminated Composite Plate ◽  
Element Analysis ◽  
First Order ◽  
Matlab Code

Abstract: Composites are used comprehensively in constructional company. Instead of conventional materials engineers are experimenting new materials every day in which composites are providing solution to many structural applications. MATLAB software is used in the investigation of static performance of laminated plates. Designing of composite laminate is very complex and requires lot of computational effort. It is very difficult to solve composite numerical problems manually. Developing MATLAB code for the analysis of laminated composite plate using finite element analysis. To determine the deflection and transverse shear stress of square laminated plate which is simply supported and subjected to uniform pressure. To explore the influence of modular ratio on deflection and transverse shear stress for different materials. Development of MATLAB code for the interpretation of first order shear deformation theory. Keywords: Laminated plate, composites, MATLAB, shear deformation theories, Finite element analysis

Structural Analysis of Variable Stiffness Laminated Plates Using First-Order Shear Deformation Theory

2014 ◽  
Author(s):  
A. H. Akbarzadeh ◽  
M. Arian Nik ◽  
D. Pasini
Keyword(s):  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Variable Stiffness ◽  
Buckling Load ◽  
Shear Stresses ◽  
Critical Buckling Load ◽  
First Order ◽  
Stiffness Design ◽  
Transverse Shear Stresses

Constant and variable stiffness strategies have been developed to design a composite laminate. With the former, each layer is designed with straight fibers that have the highest stiffness and strength in the fiber direction. With the latter, on the other hand, the stiffness can change within each layer by placing the fibers along a curvilinear fiber path. A variable stiffness design results in improved structural performance, as well as opens up opportunities to search for trade-off among structural properties. During the manufacture of a variable stiffness design with Automated Fiber Placement, certain defects in the form of gaps and overlaps could appear within the laminate and affect the laminate performance. In this study, we use the first-order shear deformation theory to assess the effect of transverse shear stresses on the critical buckling load, free and forced vibration of a variable stiffness laminate with embedded defects, an issue so far rarely examined in literature. The governing differential equations for the static analysis are first derived. A semi-analytic solution is then obtained using the hybrid Fourier-Galerkin method and the numeric time integration technique. The eigenvalue analysis is also conducted to determine the fundamental frequency and critical buckling load of the plate. It is found that the behavior of a variable stiffness plate is much more affected by the shear stresses than a constant stiffness plate. Ignoring the effect of transverse shear stresses results in 34% error in the predicted buckling load of a variable stiffness laminate with overlaps and a length-to-thickness ratio of 10.

Enhanced First-Order Shear Deformation Theory for Laminated and Sandwich Plates

2005 ◽  
Vol 72 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Jun-Sik Kim ◽  
Maenghyo Cho
Keyword(s):  
Shear Deformation ◽  
Deformation Theory ◽  
Plate Theory ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Higher Order ◽  
Laminated Plates ◽  
Sandwich Plates ◽  
First Order ◽  
Transverse Shear Strains

A new first-order shear deformation theory (FSDT) has been developed and verified for laminated plates and sandwich plates. Based on the definition of Reissener–Mindlin’s plate theory, the average transverse shear strains, which are constant through the thickness, are improved to vary through the thickness. It is assumed that the displacement and in-plane strain fields of FSDT can approximate, in an average sense, those of three-dimensional theory. Relationship between FSDT and three-dimensional theory has been systematically established in the averaged least-square sense. This relationship provides the closed-form recovering relations for three-dimensional variables expressed in terms of FSDT variables as well as the improved transverse shear strains. This paper makes two main contributions. First an enhanced first-order shear deformation theory (EFSDT) has been developed using an available higher-order plate theory. Second, it is shown that the displacement fields of any higher-order plate theories can be recovered by EFSDT variables. The present approach is applied to an efficient higher-order plate theory. Comparisons of deflection and stresses of the laminated plates and sandwich plates using present theory are made with the original FSDT and three-dimensional exact solutions.

scholarly journals A COMBINED STRAIN ELEMENT TO FUNCTIONALLY GRADED STRUCTURES IN THERMAL ENVIRONMENT

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Hoang Lan Ton-That
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Deformation Theory ◽  
Numerical Solutions ◽  
Thermal Environment ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Element Analysis ◽  
First Order ◽  
Graded Structures

Functionally graded materials are commonly used in a thermal environment to change the properties of constituent materials. They inherently withstand high temperature gradients due to a low thermal conductivity, core ductility, low thermal expansion coefficient, and many others. It is essential to thoroughly study mechanical responses of them and to develop new effective approaches for an accurate prediction of solutions. In this paper, a new four-node quadrilateral element based on a combined strain strategy and first-order shear deformation theory is presented to achieve the behaviour of functionally graded plate/shell structures in a thermal environment. The main notion of the combined strain strategy is based on the combination of the membrane strain and the shear strain related to tying points as well as bending strain with respect to a cell-based smoothed finite element method. Due to the finite element analysis, the first-order shear deformation theory (FSDT) is simple to implement and apply for structures, but the shear correction factors are used to achieve the accuracy of solutions. The author assumes that the temperature distribution is uniform throughout the structure. The rule of mixtures is also considered to describe the variation of material compositions across the thickness. Many desirable characteristics and the enforcement of this element are verified and proved through various numerical examples. Numerical solutions and a comparison with other available solutions suggest that the procedure based on this new combined strain element is accurate and efficient.

Geometrically nonlinear finite element simulation of smart laminated shells using a modified first-order shear deformation theory

2019 ◽  
Vol 30 (4) ◽  
pp. 517-535 ◽  
Author(s):  
Hanen Mallek ◽  
Hanen Jrad ◽  
Mondher Wali ◽  
Fakhreddine Dammak
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Deformation Theory ◽  
Piezoelectric Materials ◽  
Shear Deformation Theory ◽  
Nonlinear Finite Element ◽  
Shear Stresses ◽  
Geometrically Nonlinear ◽  
Element Analysis ◽  
First Order

This article investigates geometrically nonlinear and linear analysis of multilayered shells with integrated piezoelectric materials. An efficient nonlinear shell element is developed to solve piezoelastic response of laminated structure with embedded piezoelectric actuators and sensors. A modified first-order shear deformation theory is introduced in the present method to remove the shear correction factor and improve the accuracy of transverse shear stresses. The electric potential is assumed to be a linear function through the thickness of each active sub-layer. Several numerical tests for different piezolaminated geometries are conducted to highlight the reliability and efficiency of the proposed implementation in linear and geometrically nonlinear finite element analysis.

scholarly journals A Refined Simple First-Order Shear Deformation Theory for Static Bending and Free Vibration Analysis of Advanced Composite Plates

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2385 ◽  
Author(s):  
Hoang Nam Nguyen ◽  
Tran Thi Hong ◽  
Pham Van Vinh ◽  
Nguyen Dinh Quang ◽  
Do Van Thom
Keyword(s):  
Free Vibration ◽  
Shear Deformation ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Shear Stresses ◽  
Transverse Shear Strain ◽  
First Order ◽  
Advanced Composite

A refined simple first-order shear deformation theory is developed to investigate the static bending and free vibration of advanced composite plates such as functionally graded plates. By introducing the new distribution shape function, the transverse shear strain and shear stress have a parabolic distribution across the thickness of the plates, and they equal zero at the surfaces of the plates. Hence, the new refined theory needs no shear correction factor. The Navier solution is applied to investigate the static bending and free vibration of simply supported advanced composite plates. The proposed theory shows an improvement in calculating the deflections and frequencies of advanced composite plates. The formulation and transformation of the present theory are as simple as the simple first-order shear deformation. The comparisons of deflection, axial stresses, transverse shear stresses, and frequencies of the plates obtained by the proposed theory with published results of different theories are carried out to show the efficiency and accuracy of the new theory. In addition, some discussions on the influence of various parameters such as the power-law index, the slenderness ratio, and the aspect ratio are carried out, which are useful for the design and testing of advanced composite structures.

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