Guided waves in FG plates: appearing phase velocity gaps

For the first time, velocity gaps in the dispersion portraits of guided waves propagating in functionally graded (FG) traction-free plates were revealed, meaning appearance of the forbidden phase velocity range where guided waves do not exist. The observed phenomenon does not occur in homogeneous isotropic or anisotropic plates. The analysis is based on the modified Cauchy sextic formalism and exponential matrix method. The presence of forbidden phase velocities may be essential in the non-destructive diagnostics of functionally graded media by acoustic methods along with applications in theoretical geophysics.

Automated summary

This study reveals for the first time the presence of velocity gaps in the dispersion portraits of guided waves propagating in functionally graded (FG) traction-free plates, indicating the existence of a forbidden phase velocity range where guided waves do not exist. This phenomenon is not observed in homogeneous isotropic or anisotropic plates. The analysis is based on the modified Cauchy sextic formalism and exponential matrix method. The presence of forbidden phase velocities plays a crucial role in the non-destructive diagnostics of functionally graded media by acoustic methods and applications in theoretical geophysics.