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Estonian Journal of Engineering

Separation of Lamb modes at a plate edge by using orthogonality relation; pp. 283–291

Full article in PDF format | doi: 10.3176/eng.2013.4.03

Madis Ratassepp, Aleksander Klauson, Farid Chati, Fernand Léon, Gerard Maze


Lamb modes are widely used for non-destructive evaluation of plate-like structures and simple interpretation procedures for the analysis of the monitored structures are needed. In this study we apply the orthogonality relation based method for post-processing Finite Element (FE) predictions in order to separate Lamb modes at a plate edge. The reflected wave field from the free edge is a superposition of all the eigenmodes of an infinite plate. The eigenmode amplitudes of the reflected wave field are determined by applying the orthogonality-based method. Overlapping wavepackets of Lamb modes at a plate edge are simulated by using the FE model of the incident S0 mode in a plate with a crack. Time-domain signals of propagating and non-propagating modes are extracted.


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