Correlation between toughness and metal volume fraction in carbon-glass fiber laminates tested under tensile loading

ABSTRACT The conducted work investigates the correlation between toughness characteristics and metal volume fraction in Fiber Metal Laminates (FMLs) subjected to tensile loads. Aerospace grade Al 7075-T6 was utilized as the varying metal alloy in the study. The metal alloy was combined with glass and carbon fiber layers to create different configurations of FMLs with varying stacking sequences. For better adhesion between metal and composite parts, aluminum layers were etched with sodium hydroxide and chromic-sulfuric acid solutions. The laminate sheets were prepared using the hand layup method which was followed by a vacuum bagging process. Specimens were cut and tested as per ASTM standard. Results of the experimentation showed that the aluminum volume fraction is directly related to the failure strain and modulus of toughness, however, inversely proportional to the stiffness characteristics of the laminates. The highest improvement of 111% in toughness parameter in comparison to pure composite laminate was reported. Finally, a comprehensive analysis on the type of fracture behavior in comparison to classical laminate theory was critically discussed. GRAPHICAL ABSTRACT