Composite repair: On the fatigue strength of universal adhesives.

Objectives: To determine whether the composition of universal adhesives and the use of silane coupling agents could affect the fatigue strength of composite repair.

Methods: Composite samples were aged in water at 37 °C for 90 days and bonded to fresh composite to produce twin-bonded bar-shaped composite specimens (2 × 2 × 12 mm). Five universal adhesives, a multistep composite repair system and a hydrophobic solvent-free resin associated to a separate silane coupling agent application were used for bonding.