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Abstract: This paper presents the buckling analysis of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates under various in-plane mechanical loads, using the element-free kp-Ritz method. The first-order shear deformation plate theory is applied and a set of mesh-free kernel particle functions are used to approximate two-dimensional displacement fields. Effective properties of materials of the plates reinforced by single-walled carbon nanotubes (SWCNTs) are estimated through a micromechanical model based on either the Eshelby–Mori–Tanaka approach or the extended rule of mixture. Comparison study and numerical simulations with various parameters are conducted to assess efficacy and accuracy of the present method for analysis of buckling of SWCNT-reinforced composite plates. Results demonstrate that the change of carbon nanotube volume fraction, plate width-to-thickness ratio, plate aspect ratio, loading condition and temperature have pronounced effects on buckling strength of CNTRC plates as well as the boundary condition. [Copyright &y& Elsevier]

Abstract: A solution is proposed to the buckling problem formulated for a rectangular sandwich plate having all the edges fully clamped (CCCC plate) and subjected to a uniaxial compressive loading. The analysis of the out-of-plane deformation of the buckled plate is based on the equations of the first order shear deformation theory (FSDT). Galerkin method has been employed to solve the problem. Variations of the plate deflection and angles of rotation between the unloaded edges have been approximated using the solution to the bending problem for the shear deformable beam with clamped ends. The approximation of these variables between the loaded edges has been performed using trigonometry series. The solution to the problem is reduced to the calculation of the eigenvector of corresponding homogeneous system of linear equations and determination of its least component. Verification of the solution obtained has been performed using finite-element analysis. [Copyright &y& Elsevier]

Abstract: The objective of the present work is to study the effects of flexural boundary conditions on buckling and postbuckling behavior of axially compressed quasi-isotropic laminate, (+45/−45/0/90)2 s with various shaped cutouts (i.e., circular, square, diamond, elliptical–vertical and elliptical–horizontal) of various sizes using the finite element method. The FEM formulation is based on first order shear deformation theory and von Karman’s assumptions are used to incorporate geometric nonlinearity. The 3-D Tsai-Hill criterion is used to predict the failure of a lamina while the onset of delamination is predicted by the interlaminar failure criterion. It is observed that the laminates clamped and simply supported on all edges have the highest and lowest buckling and postbuckling strength, respectively, irrespective of cutouts shape and size. It is also noted that a fully clamped laminate with large size elliptical–vertical cutout can take higher compressive buckling load than the laminate without cutout for same boundary condition. [Copyright &y& Elsevier]

The vibration behaviors of functionally graded carbon nanotube (FG-CNT) reinforced composite rectangular plates subjected to in-plane loads are studied in this paper. Three types of carbon nanotube (CNT) distributions are researched in this investigation. Reddy’s third-order shear deformation theory (HSDT) is applied to evaluate the displacement fields of the plate. The equation of motion of the structural system is formulated with use of the Hamilton’s principle. The plates investigated in this study are simply-supported on two opposite edges and therefore, in order to solve the coupling set of equations of motion, the state-space Levy method is applied. Based on the Levy solution, the natural frequencies and vibration mode shapes of FG-CNT reinforced composite plates subjected to in-plane loads with different boundary conditions are presented for different thickness-length ratios and aspect ratios. Moreover, the critical in-plane loads for the buckling of different FG-CNT plates are calculated and compared. [ABSTRACT FROM AUTHOR]

Abstract: Capacity of nonlinear large deformation is favored for structures because of its indication of potential failure. Such behavior is achieved mainly through material ductility, for example yielding of steel, or so-called pseudo-ductility at the price of progressive failures of structural components. A strategy is proposed in this paper for structures made using brittle fiber reinforced polymer (FRP) materials to achieve such behavior at structural level without the failure of materials. The concept is to take advantage of the post-buckling process of certain structural components in compression, during which the structure loses its redundancy and structural deformation increases as the applied load is sustained. The concept is introduced and illustrated using the analysis of a simple truss. Experiments are then reported which visualize the proposed concept on two FRP truss structures. Experimental results from the first truss demonstrate nonlinear large deformation similar to material ideal elastic–plasticity and those from the second truss exhibit a response analogical to material strain hardening. Possible applications and developments of this concept are further suggested. [Copyright &y& Elsevier]

Thin-walled composite beams of complex sectional contour are widely used along with the traditional elements of reinforced structures. Based on the generalized theory of elasticity of thin-walled beams, the mathematical model of flexural–torsional deformation of open-profile thin-walled composite beams of non-uniform cross section under thermo-mechanical loading has been developed. To confirm the reliability of developed approach to determination of the spatial displacements of thin-walled composite beams of non-uniform cross section, several experimental studies were conducted. Based on the analysis of the range of typical profiles, for the further analysis we selected several compound cross sections for which the analytical dependences were obtained regarding displacements of their characteristic points. Our studies can serve as a base for development of the practical recommendations for the optimal designing and manufacturing of thin-walled anisotropic profiles, as well as proposing the measures to reduce the value of deformations caused by the production process. [ABSTRACT FROM AUTHOR]