title: Investigation of interfacial stiffnesses of a tri-layer using Zero-Group Velocity Lamb modes.
abstract: Zero-Group Velocity (ZGV) Lamb waves are studied in a structure composed of two plates bonded by an adhesive layer. The dispersion curves are calculated for a Duralumin/epoxy/Duralumin sample, where the adhesion is modeled by a normal and a tangential spring at both interfaces. Several ZGV modes are identified and their frequency dependence on interfacial stiffnesses and on the bonding layer thickness is numerically studied. Then, experiments achieved with laser ultrasonic techniques are presented. Local resonances are measured using a superimposed source and probe. Knowing the thicknesses and elastic constants of the Duralumin and epoxy layers, the comparison between theoretical and experimental ZGV resonances leads to an evaluation of the interfacial stiffnesses. A good agreement with theoretical dispersion curves confirms the identification of the resonances and the parameter estimations. This non-contact technique is promising for the local evaluation of bonded structures.
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Mezil
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Bruno
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Raetz
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Laurent
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Royer
authors.affiliation: ESPCI Paris Tech, PSL Research University, CNRS, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Prada