Characterisation of an Assembly made with a Cemented Plate on a Thick Substrate by Rayleigh-Sezawa waves

Author: Zouhri B.   Lebrun S.   Pouliquen J.  

Publisher: S. Hirzel Verlag

ISSN: 1610-1928

Source: Acta Acustica united with Acustica, Vol.83, Iss.6, 1997-11, pp. : 1008-1023

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

A non destructive evaluation of bonding is presented going on to the characterization of the stuck plate and the adhesive using Rayleigh-Sezawa waves for which the equations giving the velocity, the amplitudes of displacements and the distribution of energy of deformation are established (Direct problem). Afterwards the first three modes of a model which is made with a plexiglas plate bonded to a thick aluminium substrate by means of the plexiglas monomer (adhesive) are studied, the glue hardening is expressed by its shear modulus μ evolution. The velocity relative variations versus μ depend on the modes and the adhesive thickness; they can be more than 100%. The great values correspond to an energy concentration in the adhesive. Our model gives the same results as the one imagined by Pilarski in order to study adhesiveness providing that the validity domain of the last one corresponds to very thin adhesive layers. As the dispersion curves depend on the thickness-frequency product, our model is not limited to slight thicknesses. Helped by a simulation, in the inverse problem solving, it is shown how, with accuracy, the significant parameters of the model, the thicknesses and μ, are retrieved. The influence of the measurement inaccuracy is studied. Lastly, some measurements carried out on three samples made with a glass plate bonded to a glass substrate show the possibility of characterizing the adhesive nature and its ageing.