Attenuation Analysis of Lamb wave with Liquid Loading

• 1、College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.

Abstract：When Lamb wave device is used as liquid sensing, the appearance of liquid loading would lead to the energy leakage and the Lamb wave becomes leaky Lamb wave. The acoustic field components would attenuate because of the energy leakage into the liquid in the process of Lamb wave propagation. This paper establishes two-dimensional analysis model of leaky Lamb wave by adding attenuation factor in the expressions of acoustic field components. The model can provide guidance for the practical application of leaky Lamb wave. Furthermore, as to two-dimensional model, combining the clarity of surface effective permittivity method and the accuracy of boundary conditions coefficient determinant method, we obtain the leaky Lamb wave propagation velocity and attenuation factor by the method of "surface effective permittivity rough-searching" added by "boundary conditions coefficient determinant refined-searching", which can improve calculation speed and increase calculation precision simultaneously.

Keywords： energy leakage leaky lamb wave attenuation factor propagation velocity surface effective permittivity boundary conditions coefficient determinant