ANALYSIS OF CRACKED ALUMINUM PLATES REPAIRED WITH BONDED COMPOSITE PATCHES

Bonded composite repair has been recognized as an efficient and econom ical method to extend the service life of cracked aluminum components. An accurate tool for investigating the stress intensity factor in the cracked aluminum structure after repair is needed. The use of three-d imensional finite elements is computationally expensive. A simple anal ysis method using Mindlin plate theory is presented. Specifically, the aluminum plate and composite patch are modeled separately by the Mind lin plate finite element, whereas the adhesive layer is modeled with e ffective springs connecting the patch and aluminum plate. Constraint e quations are used to enforce compatibility of the patch-adhesive and a dhesive-aluminum plate interfaces, Comparison of the present stress in tensity factors for the aluminum crack with a plane boundary element a nalysis and a three-dimensional finite element analysis are made. A pr ocedure for calculating the strain energy release rate along the debon d front at the aluminum-adhesive interface is proposed.