Composite repairs to rib stiffened panels

There are several methods available for obtaining a first estimate for the design of composite repairs to cracks in thin metallic skins. One approach uses analytical formulae, which build on an analogy with the problem of a b onded symmetric lap joint (Rose LRF. An application of the inclusion analog y for bonded reinforcements. Int J Solid Struct 1981;17:827-838; Fredell RS . Damage tolerant repair techniques for pressurized aircraft fuselages. PhD Thesis, Delft University of Technology, June 1994; Baker AA, Jones R. Bond ed repair of aircraft structures. Dordrecht: Martinus Nijhoff, 1988). The p resent paper extends this methodology to include the bonded repair to rib s tiffened wing skins. To this end the present paper presents the results of a series of 3-D finite element analysis of various composite repair configu rations. This study reveals that, after repair, the stress intensity factor s exhibits an asymptotic behaviour as the crack length increases and that t his stress intensity factor is a weak function of the stiffener spacing. (C ) 2000 Elsevier Science Ltd. All rights reserved.