Experimental strength of composite sandwich panels with cores made of aluminum honeycomb and foam

Abstract

Composite sandwich panels with face sheets made of carbon/epoxy fabric and carbon/epoxy uni-directional prepreg were tested. The sandwich cores made by aluminum honeycomb and foam were cured with the face sheet at 180 °C. The aluminum core sandwich failed at the 40% failure strain of the face skin in the compression test. On the other hand, the foam core sandwich failed at the 100% failure strain of the face skin in the compression test. In the case of the aluminium core sandwich, nonhomogenous load distributions and fiber contents may affect the lower failure strain. Therefore, the specific compression strength of the foam core was 72% higher than the compression strength of the aluminum core. Failure mode analysis of sandwich panels made of aluminium honeycomb cores shows that shear failure leads to final failure. However, the specific flexural strength of the sandwich panels with aluminum cores had a slightly higher value than that of the sandwich panels with foam cores. Because the sandwich panel with aluminium cores had higher critical stress for the face wrinkling than the sandwich panel with foam cores due to higher compression modulus of aluminium cores than foam cores.

Keywords:

• sandwich panel
• honeycomb
• foam
• strength
• compression test
• flexural test