Symmetric Cross-ply Plates Research Articles

Geometrically nonlinear flexural analysis of multilayered composite plate using polynomial and non-polynomial shear deformation theories

In this paper, the geometrically nonlinear bending analysis of multilayered composite plates is carried out through a rigorous comparative study employing Green-Lagrange and von Kármán nonlinearity. The responses are analyzed for various transverse loads and boundary conditions, and emphasized the impending structural condition, which requires the consideration of full geometric nonlinearity. The study is conducted using a C0 finite element plate model using third-order and non-polynomial shear deformation theories (TSDT and NPSDT). The principle of virtual work is utilized to formulate the weak-form of governing equations, and discretized using nine-noded Lagrange elements with seven degrees-of-freedom per node. The performance of the present model has been validated by comparing present results with those available in the literature and obtained ANSYS results. The results reveal that the consideration of Green-Lagrange nonlinearity is essential for plates with all sides subjected to movable simply supported boundary conditions or with one free edge. The present study also provides a clear idea about the utilization of TSDT and NPSDT for the anti-symmetric and symmetric cross-ply plate, respectively, to get more accurate solution. Further, the effect of penalty for various theories and problems is also highlighted, and its prominent impact is asserted for some cases.

Coupled and uncoupled analyses of piezoelectric free-edge effect in laminated plates

The present paper considers the effect of electromechanical coupling on the interlaminar stresses and the electric field strengths at free edges of laminated plates with piezoelectric material properties. A comparison of coupled and uncoupled piezoelectric analyses is performed using the finite element method. Two symmetric cross-ply plates and one symmetric angle-ply laminate are investigated under uniaxial tension. It is shown that the interlaminar stresses at the free edge are significantly higher in the coupled case for cross-ply laminates, whereas the coupling effect for the symmetric angle-ply laminate is of minor significance. In addition, the occurrence of electric field strengths with singular character is revealed.

A combined theoretical and experimental investigation on free vibration of thin symmetrically laminated anisotropic plates

A generalized boundary-continuous displacement based double Fourier series solution to the boundary-value problem of free vibration of thin anisotropic fiber reinforced plastic (FRP) rectangular plates is presented. The transverse vibrational characteristics of laminated anisotropic plates with arbitrary combinations of admissible boundary conditions are theoretically investigated. Numerical results presented here pertain to the natural or resonant frequencies of five-layer symmetric cross-ply plates with all edges clamped, and rotated cross-ply anisotropic plates with all edges simply supported, which are, in turn compared with the corresponding experimental results for two sets of glass fiber reinforced plastic (GFRP) thin anisotropic rectangular plates, fabricated using two different techniques. The influence of possible defects generally encountered in the fabrication process on the experimentally obtained resonant frequencies is also discussed here.

Buckling of composite plates by global–local plate theory

The bifurcation buckling problem of laminated composite plates is formulated within the framework of a multilength scale plate theory. This theory is a combination of single-layer and layer-wise theories. It is generated by representing the displacement as the sum of global and local effects that introduce a coupling between the two length scales. Comparisons between the presently predicted buckling loads of homogeneous and orthotropic laminated plates and the exact solutions show a very good correlation. Furthermore, the theory accurately predicts the buckling load of symmetric cross-ply plates as compared with the results of a layer-wise approach. This accuracy is achieved with reduced computation expense. The global–local plate theory is general enough to incorporate delamination effects. As a result of the inclusion of these effects, the buckling loads of plates with imperfect interlaminar bonding are predicted.

Thermally induced vibration of a symmetric cross-ply plate with hygrothermal effects

The present work studies the vibration of symmetric cross ply plates under unsteady temperature effects and an unsteady moisture environment for the simply supported case

Influence of Lamination and Boundary Constraint on the Deformation of Moderately Thick Cross-Ply Rectangular Plates

Hitherto unavailable analytical solutions to boundary-value problems of moderately thick general cross-ply laminated rectangular plates, subjected to various boundary conditions, are presented. A recently developed double Fourier series-based method has been utilized to solve a system of five highly coupled linear second-order par tial differential equations (with constant coefficients), that emerge from the first-order shear deformation theory (FSDT) and the associated geometric and natural boundary con ditions. The convergence characteristics of the series solutions, especially their de pendence on lamination and boundary constraint, are numerically investigated in detail. Other numerical results presented here include (1) verification with the available analytical solutions based on the classical lamination theory (CLT) as well as FSDT, (2) investigation of the effect of length-to-thickness, length-to-width and modular ratios on the response of antisymmetric and symmetric cross-ply plates, with various boundary constraints and (3) spatial variation of displacements and moments.