Improved design methods for scarf repairs to highly strained composite aircraft structure

This paper presents an analytical method to optimise the profile of the scarf joint between dissimilar modulus adherends so that adhesive stresses are approximately uniform along the joint. The optimised scarf repair is expected to enhance joint strength and reduce the amount of material removal. Finite element analyses have been performed to both validate the optimal solution and to evaluate the use of low stiffness patch to repair carbon epoxy composites. In particular, the influence of patch lay-up on adhesive stresses has been investigated.