Analysis of guided wave propagation in highly damped viscoelastic multilayered composite structures using the biot...

Guided wave-based methodologies are a fundamental approach in structural health monitoring and non-destructive testing due to their ability to propagate over extended distances while enabling comprehensive structural coverage with minimal instrumentation and reduced inspection time. This study focuses on the analysis of highly damped viscoelastic multilayered composite structures, which are widely used in aerospace applications and require rigorous investigation to achieve accurate predictive modeling and performance assessment. Conventional viscoelastic models, such as the Hysteretic and Kelvin-Voigt formulations, exhibit limitations in accurately capturing the complex damping behaviors inherent to highly attenuative materials. To address these constraints, the Biot model is introduced as an advanced framework capable of more accurately representing viscoelastic effects within intricate composite laminates. The Moduli Ratio Convergence Method is applied with adaptations, to facilitate an in-depth analysis of wave propagation phenomena in such materials. This enhanced algorithm enables the precise determination of critical parameters, including dissipation amplitude, dispersion characteristics, phase velocity, energy velocity, and mode shape diagrams. These insights are leveraged to investigate unique wave phenomena, such as the veering of dispersion curves and frequency shifts observed in spectrograms projected onto the real plane. A qualitative analysis highlights the distinctive frequency shift phenomenon observed in the Biot model, which does not appear in the Hysteretic and Kelvin-Voigt models, providing deeper insights into the unique wave characteristics introduced by the Biot model. Comparisons with purely elastic media further explore the influence of viscoelasticity on wave propagation behaviors. To validate the analytical framework, comparisons are systematically made between viscoelastic and purely elastic cases. The findings demonstrate the robustness and applicability of the proposed methodologies, offering a reliable foundation for optimizing sensor deployment in SHM applications for anisotropic viscoelastic composite structures.