Comparative effectiveness of the mechanical behaviour of sandwich beams under uncoupled bending and torsion loadings

Sandwich geometries, mainly panels and beams, are widely used in several transportation industries, namely aerospace, aeronautic and automotive. Sandwich geometries are known for their advantages in structural applications: high specific stiffness, low weight, and possibility of design optimization prior to manufacturing. This study aims to know the influence of the number of reinforcements (ribs), and of the thickness on the mechanical behaviour of sandwich beams subjected to bending and torsion uncoupled loadings. In this study, four geometries are compared: simple web-core beam, corrugated core, honeycomb core, and joined honeycomb core. The last three are asymmetric, due to the use of odd number of ribs. The influence of the geometry on the results is discussed by means of a parameter that establishes a relation between the stiffness behaviour and the mass of the object. It is shown that all relations are non-linear, despite the elastic nature of the analysis in both the FEM software and in the practical application.