Quantifying the coupling strength of adhesivly bonded materials by investigating mode repulsion regions
* Presenting author
Abstract:
In the field of non-destructive testing, Lamb waves are often used for material characterisation. Theincreasing computational capabilities further enables complex and detailed simulations to predict thematerial behaviour in reality. Since adhesive bonding of different materials is a widely used methodin modern applications, a reliable measurement system to determine the quality of these adhesivebonds is needed.Investigations of the dispersive behaviour of acoustic waves in adhesively bonded multi-layeredwaveguides show mode repulsions in the dispersion diagrams in regions where the modes of thesingle materials would otherwise intersect. In previous works, changes of the distance between thosemodes in respect to the bonding quality are observed.The experimental data for this investigation is generated using a pulsed laser radiation excitingbroadband acoustic waves in plate like specimens which are detected by a piezoelectric ultrasonictransducer. Numerical data is generated using simulations via a semi-analytic finite element method.Using a combination of experimental and numerical data, the present work introduces an approachto determine a parameter which indicates the bonding quality in respect to an ideal materialcoupling.