<p>A method is presented to evaluate the interfacial weakness of aluminium based honeycomb sandwich structure using guided wave. Shear horizontal guided waves are sensitive to the interfacial properties and the wave particles vibration oriented parallel to the adhesive-adherent joints, making this an effective method for the adhesive bonded joints. A semi-analytical finite element (SAFE ) method with a boundary stiffness approach is used to model the interface. The effect on the SH wave through various defect kind and the various interface is analysed. For different interface stiffness analysis, the Frequency-wave-number study used to know the shear horizontal guided wave effect with the adhesive joints. The 2DFFT method reveals that while keeping kn (normal spring stiffness) fixed and varying the kt (tangential spring stiffness), at a specific limit, the wave reflection effect from the hexagonal core edges can be seen clearly for bonded case, and on the other hand, for perfect dis-bond case, SH0 mode can be seen, which reveal the adhesive interface properties in the honeycomb sandwich structure. For the experiment purpose, Periodic permanent magnet(PPM) electromagnetic acoustic transducers (EMATs) is used to generate and detect SH modes. Further short-time Fourier transform is used to distinguish between direct and reflected SH modes in the honeycomb sample. The method is experimented demonstrated on aluminium-epoxy-aluminium-epoxy-aluminium honeycomb sandwich structure samples for various kind of defects. The analysis shows a reliable non-destructive evaluation of the interface joint (kissing bonds) for classifying the bond as good or bad bonds.</p>

Evaluation of Adhesive Interface Properties in Honeycomb Sandwich Structure Using Guided Waves

Paper Proceedings: https://asmedigitalcollection.asme.org/qnde/QNDE2021/volume/85529

ASME 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE2021)

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