| Autor: |
Ying Luo, Hong Li, BaiQiang Xu, Gui Dong Xu |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Dec2010, Vol. 108 Issue 12, p123505, 6p, 2 Diagrams, 1 Chart, 3 Graphs |
| Abstrakt: |
The propagation of ultrasonic guided waves in layered viscoelastic film/substrate materials has been investigated. Based on the plane strain theory, a numerical model of the guided waves propagating in thin film on the substrate is developed in the frequency domain by employing the spectral finite element method. The surface normal displacement and the propagating characteristic are obtained and analyzed, which depends not only on the material parameters of the film, but also on those of the substrate. If the substrate velocity is faster than that of the film, the dispersion takes on the normal, otherwise, the anomalous dispersion will appear, and thin film properties for different film/substrate systems can be identified. The guided wave is attenuated gradually due to energy dissipation caused by material viscosity and rapidly at the location near the source. With the receiver distance increasing, it becomes slower. Clearly models for ultrasonic generation and propagation in layered viscoelastic film/substrate materials must include the effect of viscoelasticity on the dispersive wave. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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