Bonded repair for fuselage damage: An overall benefit to commercial aviation'

Abstract

Adhesively bonded repairs of aircraft structures are frequently used in military applications, especially at the Australian and United States Air Forces. Although bonded repairs have the capacity to provide a maintenance-free repair solution to a variety of structural damages when compared to conventional mechanically fastened repairs, commercial operators still only use them on a very limited scale. In this paper the fatigue behaviour of bonded repairs to aluminium fuselage skin structures are discussed. A fatigue test campaign with increasing complexity of the test specimen ("pyramidal approach") was carried out. Fatigue test results of cold and hot bonded repairs were compared to those of conventional riveted repairs. The results of the coupon specimens were used as input for design of the next specimen type in the "pyramidal approach" by selecting the combination of the parameters showing the most promising and most interesting results. It was found that the amount of cycles to initiate a fatigue crack in bonded repair solutions on the coupon specimens strongly depends on the adhesive type used. The fatigue lives of cold bonded coupon specimens were not longer than that of the reference riveted repair. The hot bonded coupon specimens showed a significant enhancement in fatigue performance with fatigue lives up to 6 times longer than the conventional riveted repair. © Springer Science+Business Media B.V. 2009.