Lamb waves in stratified and functionally graded plates: discrepancy, similarity, and convergence

Dispersion of Lamb waves propagating in stratified and functionally graded (FG) plates is analyzed by a newly developed variant of Cauchy sextic formalism. Comparative analysis of Lamb wave dispersion in stratified, FG, and homogenized plates reveals a substantial discrepancy in dispersion properties of the studied media, making the use of homogenization techniques almost meaningless, with the only exception at the limiting phase velocity that corresponds to vanishing frequency. At the same time, dispersion curves in the stratified plates converge to the corresponding curves in the FG plate at the increasing number of the stratification layers.

Automated summary

The dispersion of Lamb waves in stratified and functionally graded plates were analyzed using a new variant of Cauchy sextic formalism. The study found significant differences in dispersion properties among stratified, FG, and homogenized plates, making homogenization techniques almost irrelevant except at very low frequencies. With an increasing number of stratification layers, dispersion curves in stratified plates gradually converge to those in FG plates.