A three-layered sandwich element with improved transverse shear stiffness and stresses based on FSDT

For analysing deformation and stresses of sandwich structures a displacement model is developed using the first-order shear deformation theory (FSDT) for each of the three layers, the core as well as the two face sheets. An enhancement of the Extended 2D Method by Rolfes and Rohwer [Improved transverse shear stresses in composite finite elements based on first order shear deformation theory. Int J Numer Methods Engrg 1997;40:51–60] is used to calculate improved transverse stiffness and stresses. Since the numerical effort is comparatively small and only C0-continuity is required for the shape functions, the theory is suitable for finite element applications. Within this paper a corresponding three-layered finite element is presented. The performance and the applicability of the proposed element are evaluated by considering numerical examples and by comparing with other two-dimensional models.