Bending response and failure characteristics of nomex honeycomb sandwich with continuous composite facesheet encasement

Abstract

In conventional sandwich construction, the core component is typically made of Nomex honeycomb and sandwiched between two facesheets, a lower and an upper facesheet. To enhance the load-bearing capacity of this Nomex honeycomb core sandwich (NHCS) construction, we propose a NHCS construction that is continuously encased by a composite fabric facesheet on all four sides. We experimentally and numerically examine the bending response of this encased NHCS construction through a three-point bending test. We consider and discuss the effect of the orientation of the honeycomb core component and the formation of the facesheet separately to reveal the mechanism by which the composite facesheet encasing enhances the construction. Our results demonstrate that composite facesheet encasing significantly improves the bending response of the NHCS construction, with a much greater advantage than the increase in mass compared to conventional sandwich construction. The superiority of the encased composite facesheet is significantly influenced by the orientation of the honeycomb cell and the direction of the fiber ply-stacked laminate facesheet. In addition, we compare the bending response of the encased honeycomb sandwich construction with that of competing sandwiches and show that the proposed sandwich with a continuously encased composite facesheet has a superior lightweight advantage.