A Finite Element for Bending Analysis of Sandwich Composite Beams

Nowadays, the use of composite laminated structures in the automobile, railroad, civil, aeronautical, space and naval industries is growing at a huge rate. Recently, there has been a renewed interest in sandwich laminated structures, whose bending capability and performance is much better when compared to classical laminates. Sandwich structures, which are mainly used as bending components, are formed by materials with very different stiffness in the faces and in the core. Therefore the behaviour of such structures under bending conditions does not fit the classical laminate theories. Despite this, sandwich structures are simple enough to allow simplified analysis, whose mathematical accuracy depends greatly on the structure itself. In this paper the goal is to study and validate the application in bending of a developed sandwich beam element with transverse compressibility of the core. This element uses a mixed layerwise approach by considering a higher-order shear deformation theory (HSDT) to represent the displacement field of the core and a first-order shear deformation theory (FSDT) for the face layers. Results are compared with three-dimensional finite element solutions and validation is also conducted with values retrieved experimentally.