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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2006, Vol. 27 ›› Issue (4): 713-719.

• 论文 • Previous Articles     Next Articles

Characterization of Surface Properties of Layered Structures Using Nonlinear Lamb Wave Approach

DENG Ming-xi   

  1. Faculty of Physics, Logistics Engineering University, Chongqing 400016, China
  • Received:2005-01-18 Revised:2005-03-31 Online:2006-08-25 Published:2006-08-25

Abstract: The nonlinear Lamb wave approach is presented for characterizing the surface properties of layered structures. The influences of changes in surface properties of layered structures on the effect of second-harmonic generation by Lamb wave propagation are analyzed. Based on the Ritec-SNAP system, the nonlinear Lamb wave experimental system is established. When the areas and thicknesses of coating on the surface of a given layered structure change, the amplitude-frequency curves both of the fundamental waves and the second harmonics of Lamb waves are measured under the condition that Lamb waves have a strong nonlinearity. It is found that the micro-changes in surface properties will obviously affect the efficiency of second-harmonic generation by Lamb wave propagation. The stress wave factor (SWF) in acousto-ultrasonic technique is used for reference. The SWFs of Lamb waves are defined. The experimental results show that the SWFs of second harmonics of Lamb wave propagation can well and truly characterize the changes in surface properties of layered structures.

Key words: surfaces and interfaces of materials, layered structure, Lamb waves, nonlinearity, second harmonic, stress wave factor

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