Environmental effects on mechanical properties of glass/epoxy and fiber metal laminates, Part II: Isothermal aging

The aim of this study is to investigate effects of isothermal aging on mechanical properties of fiber metal laminates (FMLs) and glass/epoxy composites. For this purpose, both materials were fabricated using the wet lay-up manufacturing technique under vacuum pressure. Both the glass/epoxy composites and the FML specimens were then subjected to isothermal aging (130°C, dried air) for up to 5 weeks. After the isothermal aging, the specimens’ weight loss, caused by thermo-oxidative conditioning, was evaluated. Bending and Charpy impact tests were conducted on both the unaged and aged specimens to examine the isothermal condition-ing’s effect on the mechanical properties of studied materials. Experimental results revealed that isothermal aging severely affected impact strength in the form of embrittlement and re-duced ductility. However, no significant reduction was found in the flexural stiffness of iso-thermally aged FML and glass/epoxy specimens.