Flexural and Impact Properties of Stainless Steel based Glass Fibre Reinforced Fibre Metal Laminate under Hygrothermal Conditioning

Fibre metal laminates (FMLs) have appeared as the most suitable materials for shipbuilding, aeronautical and aerospace applications due to their superior mechanical properties over traditional materials. In this paper, degradation in flexural and impact properties of glass fibre/epoxy composite (GF/E composite) and stainless steel glass fibre/epoxy fibre metal laminate (SS FML) due to hygrothermal conditioning has been investigated for marine applications. Hand lay-up process was used for specimen preparation according to ASTM standards. Distilled water and seawater were used for hygrothermal conditioning at 40°C and 70°C for three months. The three point bend test was performed on universal testing machine using a three point bend fixture. The pendulum type impact testing machine was used to perform Izod impact test. Due to the preventive action of outer stainless steel layers against moisture ingestion, the reduction in mechanical properties of SS FML was less as compared to GF/E composite. SS FML and GF/E composite exhibited low moisture absorption rate in seawater at both temperatures as high salt content in seawater reduces the moisture diffusion process into the composite matrix.