Experimental evaluation of hygrothermal degradation of stainless steel fibre metal laminate

Abstract

In this research paper, the tensile and compressive strength degradation of glass fibre/epoxy composite (GF/E composite) and stainless steel glass fibre/epoxy fibre metal laminate (SS FML) due to hygrothermal conditioning have been investigated. The tensile and compression test samples were prepared using hand lay-up process according to ASTM D3039/D3039M – 14 and ASTM D695 – 15 standards respectively. Two aqueous environments, i.e., distilled water and sea water were used at two different temperatures (40 °C and 70 °C) for hygrothermal conditioning up to three months. Tensile and compressive strengths of SS FML were reduced by 23.4% and 32.6% respectively in distilled water at 70 °C. The highest reduction in tensile and compressive strengths of GF/E composite was recorded in distilled water at 70 °C as 29.8% and 36.8% respectively. The maximum weight gain for tensile specimens (0.44% by SS FML and 1.93% by GF/E composite) was lower than those obtained for compression specimens (1.48% – SS FML and 2.97% – GF/E composite) due to the geometrical difference in between them. The failure modes of both tensile and compression samples were investigated using scanning electron microscope (SEM). Unconditioned and hygrothermally conditioned tensile specimens fail due to fibre breakage and delamination respectively, whereas, the compression specimens fail only because of delamination between GF/E layers.