Buckling analysis of CNT reinforced functionally graded laminated composite plates

Vibration characteristic of moderately thick functionally graded carbon nanotube reinforced composite skew plates

Free vibration analysis of functionally graded carbon nanotube-reinforced composite triangular plates using the FSDT and element-free IMLS-Ritz method

Computation of vibration solution for functionally graded carbon nanotube-reinforced composite thick plates resting on elastic foundations using the element-free IMLS-Ritz method

The effect of transverse shear deformation on the buckling of two-layer composite columns with interlayer slip

The effects of transverse shear deformations and structural damping on the flutter phenomena of a composite rotor blade in hover have been investigated using the finite element method. First-order shear deformation theory with rotary inertia effects and a damped element model of composite laminates are employed for the structural formulation. A quasisteady aerodynamic theory with a dynamic inflow model is used. Torsion-related out-of-plane warping and noncirculatory aerodynamic components are also incorporated in the formulation. Using these structural and aerodynamic tools, several numerical studies are carried out, first to validate the current approach and second to show the effects of transverse shear deformations and structural damping on the aeroelastic stability of a composite rotor as a function of fiber orientation. The predictions derived by the frequency analysis of this model are found to be more accurate than those given by an alternative approach compared with experimental data. It is shown that the transverse shear flexibility tends to lower the frequency of the rotor, and generally has a destabilizing effect on the lag mode and a stabilizing effect on the flap mode. It is also presented that the magnitude of structural damping can be controlled by changing ply orientation angle. CT cd c, EA

The present study deals with the dynamic stability of laminated composite pre-twisted cantilever panels. The effects of various parameters on the principal instability regions are studied using Bolotin's approach and finite element method. The first-order shear deformation theory is used to model the twisted curved panels, considering the effects of transverse shear deformation and rotary inertia. The results on the dynamic stability studies of the laminated composite pre-twisted panels suggest that the onset of instability occurs earlier and the width of dynamic instability regions increase with introduction of twist in the panel. The instability occurs later for square than rectangular twisted panels. The onset of instability occurs later for pre-twisted cylindrical panels than the flat panels due to addition of curvature. However, the spherical pre-twisted panels show small increase of nondimensional excitation frequency.

In the present study, an analytical solution for the static analysis of orthotropic plates under combined thermal and mechanical loading has been developed using the hyperbolic shear deformation theory. The hyperbolic sine and cosine function is used in the displacement field in terms of thickness coordinate to represent the effect of transverse shear deformation. The most important feature of the theory is that transverse shear stresses can be accurately calculated by the direct constitutive equation approach. The present theory contains the same number of dependent variables as in the first-order shear deformation theory. The governing equilibrium equations and boundary conditions of the theory are obtained using the principle of a virtual work. Simply supported orthotropic plates subjected to a sinusoidal and uniformly distributed thermal and mechanical load is considered for the detail numerical study. Navier solution technique is employed for the simply supported plates. The program has been developed in FORTRAN. Results are obtained for displacements and stresses. The present solutions are compared with those obtained by other researchers. The results are in good agreement with the solution presented by other shear deformation theories.

Transient analysis of FGM and laminated composite structures using a refined 8-node ANS shell element

C0 triangular elements based on the Refined Zigzag Theory for multilayer composite and sandwich plates

Bending and vibration behaviors of matrix cracked hybrid laminated plates containing CNTR-FG layers and FRC layers

Zeroth-order shear deformation micro-mechanical model for composite plates with in-plane heterogeneity

In the present paper, the asymmetrical nonlinear response of a clamped functionally graded shallow spherical shell is subjected to uniform external pressure. It considers the effects of thermal stresses by both of the theories, Classical Laminate Theory, CLT and First-Order Shear Deformation Theory FSDT. Material properties are graded in the thickness direction according to the power-law distribution in terms of the volume fraction of the constituents. Mechanical and thermo-mechanical properties are assumed to be temperature-independent and linear elastic. All of the governing equations are derived by aid of first-order transverse shear deformation theory considering geometrical nonlinearity. The nonlinear differential equation system is solved employing Galerkin method. Buckling and post-buckling analysis have been done according to one-term deformation mode by the closed form relation of load-deflection that shows the equilibrium path. Parametric studies are conducted to bring out the effects of shear deformation on the equilibrium path in different geometries and boundary conditions. Numerical results are presented in graphical arrangement, showing that the geometrical nonlinear equilibrium paths. The effects of shear deformation on the equilibrium path are considered by comparing the results from FSDT and CLT and was verified by nonlinear finite-element method.

An analysis is presented for the study of the effect of transverse shear deformation on the natural frequencies of layered composite paraboloidal shells. The applicability of linear shell theory due to Reissner is assumed and governing equations are solved for the natural frequencies using the transfer matrix approach. The results of the present analysis are compared with the results for paraboloidal shells reported in the literature and good agreement is found. Transverse shear deformation effects are carried out separately for axisymmetric torsional vibration modes, axisymmetric bending-extensional vibration modes and nonsymmetric vibration modes. The variation of the effect of transverse shear deformation with respect to different rim boundary conditions, geometry of the paraboloid, material type (isotropic-orthotropic), lamination arrangement and particular meridional and circumferential vibration modes is investigated.

In this paper, vibration features of variable thickness rectangular viscoelastic nanoplates are studied. In order to consider the small-scale and the transverse shear deformation effects, governing differential equations and relevant boundary conditions are adopted based on the nonlocal elasticity theory in relation to first-order shear deformation theory of plates. The numerical solution for the nanoplate vibration frequencies is proposed applying the differential quadrature method, as a simple, effective and precise numerical tool. The present formulation and solution method are validated showing their fast convergence rate and comparison of results, in limited cases, using the available literature. Excellent agreement between the obtained and available results is observed. The effects of structural damping coefficient, boundary conditions, aspect ratio, nonlocal and variable thickness parameters on viscoelastic nanoplates vibration behaviour are studied in detail.

In the present paper, using an improved Reissner’s variational theorem along with Berger’s hypothesis, a set of governing equations which include the effects of transverse shear deformation and rotatory inertia is derived for the large amplitude free vibrations of plates composed of a transversely isotropic material. Applying the possibility of neglecting the rotatory inertia in primarily flexural vibration (discussed in the previous work [1]2), the lateral free vibrations of simply supported plates are treated in detail and the solution is compared with those of previous investigators. The free vibration of beams is studied as a special case of plates, while the small amplitude vibrations are treated as a special case of large amplitude vibrations. The numerical results show that the effect of transverse shear deformation is significant when applying to the plate constructions made of pyrolytic graphite-type materials.