Non contact probing of interfacial stiffnesses between two plates by zero-group velocity Lamb modes

Sylvain Mezil (1) , Jérôme Laurent (1) , Daniel Royer (1) , Claire Prada (1)

1 IL - Institut Langevin - Ondes et Images (UMR7587)

A non contact technique using zero-group velocity (ZGV) Lamb modes is developed to probe the bonding between two solid plates coupled by a thin layer. The layer thickness is assumed to be negligible compared with the plate thickness and the acoustic wavelength. The coupling layer is modeled by a normal and a tangential spring to take into account the normal and shear interfacial stresses. Theoretical ZGV frequencies are determined for a symmetrical bi-layer structure and the effect of the interfacial stiffnesses on the cut-off and ZGV frequencies are evaluated. Experiments are conducted with two glass plates bonded by a drop of water, oil, or salol, leading to a few micrometer thick layer. An evaluation of normal and shear stiffnesses is obtained using ZGV resonances locally excited and detected with laser ultrasonic techniques.

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Sylvain Mezil, Jérôme Laurent, Daniel Royer, Claire Prada. Non contact probing of interfacial stiffnesses between two plates by zero-group velocity Lamb modes. Applied Physics Letters, 2014, 105, pp.1605. ⟨10.1063/1.4890110⟩. ⟨hal-01062897⟩