Numerical analysis of the behaviour of repaired inclined cracks with bonded composite patch having two adhesive bands in aircraft structures

Abstract

Adhesive in bonded composite repair plays two opposite roles. The first role ensures the load transfer between the composite patch and the cracked aluminium component. The second ensures the connection between these two structures in order to avoid adhesive failure. In this study, a method of adhesive deposition for repair is proposed, it divides the adhesive layer into two bands with different properties. The first band is used on the crack region to ensure stress transfer and the second is used beyond the crack region to avoid adhesive failure. The case of mixed mode loading (inclined crack) has been studied. The mode I and mode II stress intensity factors (SIFs) at the crack tip are computed for this repair configuration using the finite-element method. The obtained results show that the two SIFs at the crack tip are considerably reduced by the difference of properties between the two adhesive bands, which can improve the fatigue life of cracked structures.

Keywords

bonded composite repair two adhesive bands crack mode I stress intensity factor mode II stress intensity factor adhesive stress finite-element method

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