A mechanical model for two-dimensional cellular sandwich cores with general geometry

The aim of the present study is the determination of the effective elastic properties of two-dimensional cellular materials using cellular sandwich cores as a material example. A strain energy-based homogenisation procedure is proposed which assumes equivalence of microstructure and effective medium if the strain energy stored in a representative volume element is equal whether the real microstructure or the effective medium is considered provided that the strain state in both cases is equal in the average sense. Within this scheme, the strain energy can be evaluated either analytically or numerically. Both approaches are found to agree well in two examples considering commercial sandwich core geometries.