Comprehensive characterization of AA 2024T3 fiber metal laminate with nanosilica-reinforced epoxy based polymeric composite panel for lightweight applications

Fiber metal laminates (FMLs) are a hybrid composite material used in aircraft structural parts. They are fabricated by stacking thin aluminum sheets with a fiber-reinforced polymer composite. In this research work, nanosilica was mixed with epoxy resin in different weight percentages such as 0, 1, 3, 5, and 7 wt% for the preparation of FML. Nanosilica was used as a secondary reinforcement in the epoxy resin to improve the interfacial bonding and mechanical strength of the FML. The morphology and chemical compositions of the cured nanosilica-dispersed epoxy resin and aluminum were examined using Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscope, and energy-dispersive X-ray analysis. Thermogravimetric analysis was used to investigate the thermal stability of epoxy before and after the addition of nanosilica. FML was prepared using the hand layup and compression molding processes by sandwiching thin aluminum alloy sheet and E-glass fiber. The FML specimens were cut using an abrasive water jet machine as per ASTM standards for determining their mechanical characteristics such as tensile strength, flexural strength, and short-beam strength. Vibrational analysis was undertaken, and the natural frequency and damping factor for the FML specimens were determined. The results revealed that the tensile strength of pure FML was increased by 7% for 3 wt% nanosilica-dispersed FML. Flexural and interlaminar shear strength was increased by 30.5% and 10.9%, respectively for the 1 wt% nanosilica-dispersed FML was compared to pure FML.