First-Order Shear Deformation Theory Variants for Curved Sandwich Panels

Due to the curvature, the first-order shear deformation theory for curved sandwich panels is not a direct extension of the corresponding one for flat panels; thus, it is formulated accordingly, and its unique features, such as the reference curve, are discussed. Three versions of the first-order shear deformation theory are formulated: the one based on a direct variational formulation based on the assumed through-thickness displacement field (termed "basic"); one based on the definition of an equivalent shear modulus for the section (termed "Geq"); and one based on derivation of a shear correction factor, which is considered in conjunction with the equivalent shear modulus. A comparison of the results between a previously formulated benchmark elasticity solution and the three variants of the first-order shear deformation theory is presented. In addition, the results are compared with the classical theory for curved sandwich panels, which does not include transverse shear. The shear correction factor formula derived for sandwich curved panels is proven to converge to the homogeneous flat-plate value of 5/6 in the limit.