In-situ measurement of the stiffness of the foam layer in foam-adhesive-bonded structures

Abstract

In this paper, a method is proposed which permits estimating the stiffness of the foam layer when the adherend (ie, the strip) is subjected to point loads representing the forces exerted by the fastners. The surface of the adherend is of mirror-like finish, as is found in the disk-drives industry. From the Moire fringe pattern generated with the use of the mirror-image method, the deflection of the adherend due to the point loads is deduces. Treating the foam layer as of the Winkler type, the magnitude of its stiffness is iterated using the theory of beams on elastic foundation.