Study On Acoustic Propagation Characteristics In Planar Layered Solid Media

The propagation regularity of sound waves in multi-layered media is an important aspect of acoustic logging theory.In this paper,the reflection and transmission properties of planar waves in layered media,the incident problem of finite beam incidence and the dispersion characteristics of Lamb wave and Rayleigh wave are mainly studied.The reflection and transmission properties of planar waves in layered media are the basis for studying the theory of elastic wave propagation in solids.In this paper,the transfer matrix method is used to analyze the quantitative relationship between the reflection coefficient,the transmission coefficient and the acoustic frequency,the angle of incidence,the thickness of the dielectric layer by the water immersion monolayer solid media model,the two-layer solid media model and the three-layer solid media model,and obtain the curve of reflection coefficient and transmission coefficient varies with each parameter.The study of the reflection and transmission properties of plane waves is the basis for the analysis of the incident problem of finite beam.In this paper,based on the calculation results of the plane waves,the incident problem of finite beam is analyzed by the angle spectrum method.At first,the total sound field distribution of the finite beam incident on the dielectric interface is calculated numerically.Then,the distribution curve of the acoustic transmission energy in the f-k domain is calculated when the finite pulse penetrates the solid thin plate model,and the relationship between the curve and the Lamb wave dispersion curve in the plate is analyzed.Finally,the distribution of the total sound field a nd the displacement in the plate when the finite width beam penetrates the solid thin plate model with different angular spectra is analyzed.Rayleigh wave is a kind of important guided waves propagating near the surface of layered media.In this paper,the dispersion curve of Rayleigh wave on the surface of three-layer dielectric model is numerically calculated by means of transfer matrix method,and the characteristics and causes of Rayleigh wave's zigzag dispersion curve are analyzed and summarized on the basis of previous research work.