Fatigue, fracture toughness and DMA of biosilica toughened epoxy with stacked okra fiber and Al 2024‐T3 fiber metal laminate composite

Abstract In this present study, a natural fiber‐based fiber metal laminate (FML) was fabricated for various engineering applications. The primary aim of this present investigation was to study the effect of adding natural fiber along with metal and the effect of the surface‐treatment process on the reinforcements on load‐bearing and thermo‐mechanical properties. Okra fiber woven mat, aluminum 2024‐T3 foil and rice husk‐derived biosilica were used as reinforcements. For surface treatment, the metal foil was sandblasted whereas the okra fiber and biosilica were silane‐treated. The FML was fabricated using the vacuum bag method utilizing as‐received and silane‐treated reinforcements as two separate models. According to the results, the addition of Al foil and okra fiber improved the storage modulus and loss factor of about 4.2 GPa and 0.39 for surface‐treated reinforcements. Similarly, maximum fracture toughness and energy release of 39.42 MPa √m and 0.76 MJ/m 2 for surface‐treated EOA2 composite designation. Moreover, the addition of okra fiber and Al foil increased the fatigue life counts up to 54,266, 48,116, and 26,263 for surface‐treated EOA2 composite at 30%, 60%, and 90% of ultimate tensile stress (UTS). Such thermo‐mechanical and load‐bearing properties improved FMLs could be used in automotive, aircraft, drone and other industrial applications requiring high structural rigidity and load absorbing capability.