An experimental/numerical study on bending behaviour of composite sandwich panels

This paper deals with the mechanical characterization of a composite sandwich material typically used in boating industry; skins are made of epoxy pre-preg fiberglass while core is made by syntactic foam obtained using epoxy resin as well. Actually, analytical and numerical simulations heavily rely on mechanical properties of materials but need correct estimates since even small deviations may cause large inaccuracies of structural assessments. Finite element (FE) analyses of large scale collapse tests, integrated by traditional small scale tests, allowed the validation of the material properties values by comparing global behaviour as well as local strains measured on external faces and between skins and core of panels. Moreover, the first ply failure (FPF) and the post FPF behaviour of the sandwich structure have been assessed, hence calibrating the FE models and highlighting scale and fabrication effects.