FAILURE MECHANISMS IN BONDED PATCH REPAIRED STRUCTURES

Naveen Rastogi, B. P. Deepak, Som R. Soni and Arvind Nagar

ABSTRACT

Bonded repair of damaged metallic structures using composite patches is finding an increased application in the enhancement of service life of aging aircraft fleets. In this work, the effect of bonded patch repair on the stress fields in the skin, patch and adhesive is studied. The stress field in the bonded composite patch repaired structure is analyzed using three different analytical techniques. The numerical example studied indicates a significant reduction in the magnitude of stresses in the patch repaired skin in the vicinity of damaged zone which is modeled as a rectangular slit in the skin. Also, the presence of high stress gradients at the material interfaces is found to be the characteristic of the bonded repaired structures, and can lead to debonding and failure of the interfaces.