Numerical estimation of the mass gain between double symmetric and single bonded composite repairs in aircraft structures

In this study, the three-dimensional finite element method is used to analyse the advantages of the double symmetric composite repair compared to the single one in aircraft structures by analysing the mass again between the two techniques. This gain is defined as the ratio between the thickness of the double and single patches giving the same stress intensity factor (SIF) at the crack tip. The obtained results show that the mass gain resulting from the use of the double symmetric repair is important because of the double stress absorption. It also shown that, the adhesive properties must be optimised in order to improve the advantages of double symmetric composite repair.