Prof. habil. dr. Rimantas Barauskas
Kauno Technologijos Universitetas, Informatikos fak.
Taikomosios informatikos katedra

Influence of the numerical dispersion effects in the modelling of ultrasonic measurements
Julius Prikšaitis, Liudas Mažeika, Rimantas Barauskas, Egidijus Žukauskas, Andrius Kriščiūnas.

The modern structures in aerospace, transport, wind energy and other industries contain components manufactured of composite materials. One of the advanced techniques used for inspection and monitoring of such structures are based on the application of guided ultrasonic waves. Numerical simulation is one of the most efficient tools enabling adequate interpretation of a signal. However, the necessity to relate the sampling steps in time and space domains with frequency and wavelength of the ultrasonic waves propagating within the object under investigation often leads to unacceptably long simulation time. Employment of coarser meshes tends to create additional problems caused by the numerical dispersion effects. It leads to the distortion of the shape of the simulated signal and mismatches against the experimental results. The objective of this work was to investigate the numerically caused distortions in simulated ultrasonic waves and to develop the technique enabling to minimize their influence. The analysis has been carried out by investigating the propagation of wideband ultrasonic waves in materials with known elastic properties by using the finite element model. The calculated signals have been used for the estimation of the propagation velocity, which has been compared against the corresponding wave velocities obtained by the analytical formulae and against signal velocities measured experimentally. As a result of the investigation, the rules enabling to determine a well-balanced set of modelling parameters have been developed. It was demonstrated that the models developed on the base of this set of parameters enable to reduce the numerical dispersion errors, as well as, the simulation time. (C) 2015 The Authors. Published by Elsevier B.V.KeywordsAuthor Keywords:Lamb wave; dispersion; group velocity; simulation; experiment; finite element modellingKeyWords Plus:WAVES
PublikacijaPhysics procedia : Proceedings of the 2015 ICU international congress on ultrasonics, Metz, France, May 10-15, 2015, 2015, vol. 70, p. 532-536
Duomenų bazėConference Proceedings Citation Index - Science (Web of Science)
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