Quantitative accessibility of delamination in composite using lamb wave by experiments and FEA

Delamination in composite structures plays a major role in lowering structural strength and stiffness, consequently downgrading system integrity and reliability. The aim of this study was to show that Lamb waves may be effectively generated using piezoelectric actuators embedded within a composite plate for use in health monitoring applications. A Lamb wave-based quantitative identification technique for delamination in VARTM (vacuum assisted resin transfer molding) composite structures was established. The propagation of Lamb waves in composite plates was evaluated using dynamic FEM analysis, then an experiment was carried out to verify the validity of the analytical study. The study assessed damage in the plates by fusing information from multiple sensing paths of the embedded network. To eliminate interference, a wavelet transform technique was applied to purify the acquired Lamb wave signals. The results showed that satisfactory detection of defects could be achieved with the proposed method.