Indentation of Sandwich Beams with Functionally Graded Skins and Transversely Flexible Core

Abstract

AbstractImproved high-order sandwich beam theory is used to model the local deformation under the central indenter for sandwich beams with Aluminum/Alumina FG skins loaded under three-point bending. First shear deformation theory (FSDT) is used for the FG skins while three-dimensional elasticity is used for the flexible core. By using the model to consider the way in which different wavelengths of sinusoidal pressure loading on the top FG skin are transmitted to the core and to the bottom FG skin, two spreading length scales λt and λb are introduced and calculated. λt and λb, which are two functions of the beam material and geometric properties, characterize the length over which a load on the top surface of a beam is spread out by the skins and the core. When semi-wavelength is greater than λt (or λb), the contact load at the top FG skin is transmitted relatively unchanged to the core (or to the bottom FG skin). Conversely, when L/m < λt (or λb), the applied load is spread out by the top FG skin (or by the top FG skin and the core) over a length of the order of λt (or λb). Reasonable agreement is found between theoretical predictions of the displacement field under the indentation loading and FEM results of ANSYS using a sandwich beam with functionally graded skins and transversely flexible core.KeywordsSandwich beamIndentationFirst order shear deformation theoryFunctionally graded skinsFlexible core