Characterization of moisture effects on novel agglomerated cork core sandwich composites with fiber metal laminate facesheets

Abstract

A sandwich material would be an attractive structural candidate for marine applications as long as it can retain its environmental durability. However, the susceptibility to moisture attacks is still the major drawback of sandwich materials in comparison to the single skin laminates. Hence, this paper aims to study the effect of moisture absorption on the mechanical behavior of a newly developed sandwich structure, which is intended for use as a water-resistant constructive system in marine industries. For this purpose, an eco-sandwich material consisting of fiber metal laminate facesheets bonded to a core of agglomerated cork was successfully designed and manufactured. To investigate the moisture effects on possible mechanical degradation, a certain number of sandwich specimens were immersed in distilled water for a period of 100 days. For comparison, a sandwich structure with the commercial E-glass–epoxy facesheets was also manufactured and exposed to the aforementioned conditioning process. Eventually, the flexural, buckling and impact behaviors of the conditioned specimens were evaluated and compared with those of dry specimens. Results showed that that water immersion exposure effectively contributed to reducing the mechanical properties of sandwich specimens with E-glass–epoxy facesheets compared with those having fiber metal laminate facesheets. Moreover, it was found that the excellent mechanical properties of the fiber metal laminates in combination with the high environmental durability of agglomerated cork offer a synergistic effect yielding a sandwich martial with various advantages in terms of eco-friendly, high environmental resistance, and superior mechanical properties.