Influence of volumic fraction of adhesive in elastic and viscous thin bonded Aluminum/Adhesive/Aluminum plate on Lamb modes that have ZGV modes.

Before a nondestructive testing process gets set up, the sensitivity of the Lamb waves to the bonded plate's properties must be well understood. The dispersion and attenuation curves in thin bonded Aluminum/Adhesive/Aluminum plate are calculated by the Stiffness matrix method. The increase in the volumic fraction d caused the appearance of backward mode in the S and S dispersion curves.

Elastic constants measurement of anisotropic Olivier wood plates using air-coupled transducers generated Lamb wave and ultrasonic bulk wave.

A hybrid elastic wave method is applied to determine the anisotropic constants of Olive wood specimen considered as an orthotropic solid. The method is based on the measurements of the Lamb wave velocities as well as the bulk ultrasonic wave velocities. Electrostatic, air-coupled, ultrasonic transducers are used to generate and receive Lamb waves which are sensitive to material properties.