Experimental and computational analysis of hybrid fiber metal laminates for vibration behavior in marine structural applications

Structural advancements in underwater vehicle design necessitate lightweight materials, driving interest in Fiber Metal Laminates (FMLs), known for their high specific strength, stiffness, and corrosion resistance. This study investigates the vibration response of FMLs through combined experimental and numerical analyses, specifically evaluating the novel effects of layerwise acoustic impedance matching on vibration damping within the 0-500 Hz frequency range, which aligns with ocean current frequencies. Various FML stackup sequences were characterized through ASTM E756-05 compliant experiments and ANSYS Harmonic Response simulations. Notably, the introduction of paperboard-epoxy ply results in a rightward shift in natural frequencies, while the exclusion of the metallic face ply leads to a leftward shift across different stackups. Moderate agreement between experimental and numerical results for material modulus highlights the robustness of our findings. Overall, this study provides valuable insights for leveraging FMLs in submersible hulls, underscoring their potential for enhanced vibration-damping characteristics in marine environments.