The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 1995
Filed:
Sep. 15, 1993
Luc Piche, Montreal, CA;
Daniel Levesque, Terrebonne, CA;
National Research Council of Canada, Ottawa, CA;
Abstract
An ultrasonic interferometry technique for composite structures such as metal/polymer/metal structures exhibits high sensitivity to interfacial properties, even at usual ultrasonic wavelengths. A model for the ultrasonic response of multilayered media accounts for viscoelasticity. Results of numerical calculations point out scaling features for interfacial properties in terms of specific stiffness S. A method is provided for characterizing the interfacial adhesion in a multilayer composite in terms of the parameter S. The multilayer composite is ultrasonically irradiated with a pulsed signal to obtain a signal characteristic of the interfacial adhesion between the multilayers. A model is provided of the multilayer composite that includes at least two additional layers which model the behaviour of the interface between the composite layers. From the model, given various input parameters such as thickness of the two additional layers and the viscoelastic properties of the layers, a plurality of spectra, characteristic of interfacial adhesion between the modeled multilayer composite are obtained. The spectrum related to the ultrasonic signal is compared to the plurality of the modeled spectra and a best fit or match is obtained. The value of S relating to the best fit model is determined to be the value which characterizes the interfacial adhesion between layers of the irradiated composite.