Equivalent properties for corrugated cores of sandwich structures: A general analytical method

Corrugated core sandwich structures are increasingly used as multi-functional components in many industrial areas. In order to perform efficient finite element analysis, the sandwich construction can be represented as a multi-layer two-dimensional continuum. To do so, the complex shaped core is usually represented as an orthotropic homogeneous layer. The challenge is therefore to determine the mechanical properties of the equivalent material to accurately model the sandwich structure. Several methods exist in the literature, but analytical formulations are only available for specific types of core. In this paper, a general analytical formulation to characterize the equivalent material is proposed. The generality of the proposed approach consists in its ability to model every corrugation geometry, overcoming the main limitation of existing analytical formulations. Both beam and shell sandwich structures are modeled. Given the importance of the out-of-plane properties, all parameters for a Reissner–Mindlin representation are studied. Moreover, also non-symmetric corrugation profiles are easily processed. Thanks to its versatility, the method is validated by means of an extensive comparison with previous authors on the most common corrugation geometries. In addition, when agreement is not found on results, finite element simulations are set up to prove the precision and accuracy of the proposed formulation.