Keywords: sandwich, radial basis functions, multiquadrics, layerwise theory.

The classical laminate plate theory and the first-order shear deformation theory [1,2,3,4,5] describe with reasonable accuracy the kinematics of most laminates. Higher-order theories can represent the kinematics better, may disregard shear correction factors and yield more accurate transverse shear stresses [6,7,8,9,10,11]. All such theories consider the same degrees of freedom for all laminate layers. In some cases, particularly in sandwich appplications, the difference between material properties makes it difficult for such theories to fully accomodate the bending behaviour. In fact most of them do not correctly represent the transverse shear stresses. Another set of theories that were introduced back in the 1980's are the layerwise theories, that consider independent degrees of freedom for each layer. The layerwise theory of Reddy [12] is perhaps the most popular layerwise theory for composite and sandwich plate analysis. In this work we adopt a somewhat different kind of a layerwise theory, based on an expansion of Mindlin's first order shear deformation theoryin each layer. The displacement continuity at layer's interface is garanteed. Also such theories produce directly very accurate transverse shear stress, although constant, in each layer. Some interesting layerwise or zig-zag theories have also been presented by Mau [8], Chou and Corleone [13], Di Sciuva [14], Murakami [15], Ren [16] and Carrera [17].

This paper considers the analysis of composite laminated plates by multiquadrics RBFs [18,19] and by using a layerwise theory. This combination allows the accurate analysis of isotropic, composite and sandwich plates of arbitrary shape and boundary conditions.

1

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