Buckling Behaviour of Carbon–Epoxy Adhesively-Bonded Scarf Repairs

Abstract

The present work is dedicated to the experimental and numerical study of the buckling behaviour under pure compression of carbon–epoxy adhesively-bonded scarf repairs, with scarf angles varying from 2 to 45°. The experimental results were used to validate a numerical methodology using the Finite Element Method and a mixed-mode cohesive damage model implemented in the ABAQUS^® software. The adhesive layer was simulated using cohesive elements with trapezoidal traction–separation laws in pure modes I and II to account for the ductility of the adhesive used. The cohesive laws in pure modes I and II were determined with Double Cantilever Beam and End-Notched Flexure tests, respectively, using an inverse method. Since in the experiments interlaminar and transverse intralaminar failures also occurred, cohesive laws to simulate these failure modes were also obtained experimentally following a similar procedure. Good correlations were found between the numerical predictions and experimental results for the elastic stiffness, maximum load and the corresponding displacement, plateau displacement and failure mode of the repairs.

Keywords:

• FRACTURE
• FINITE ELEMENT METHOD
• COHESIVE DAMAGE MODEL
• REPAIR