Injection repair of composites for automotive and aerospace applications

The continuous growth of composite materials for aerospace and automotive applications reinforces the need for efficient and effective repair procedures. Common bonded scarf or doubler repairs are well suited to critical structural applications, however they can be excessively demanding for lesser repair applications. Alternatively, previous research has shown low viscosity resin injection repairs to have considerable potential for the restoration of compressive strength in delaminated monolithic structures. This work extends such methods to the repair of dry spot defects in thick Carbon Fibre Reinforced Polymer (CFRP) laminates, and skin disbonds in Glass Fibre Reinforced Polymer (GFRP) / foam sandwich structures. Injection repairs have been conducted, under vacuum, using low viscosity room temperature curing epoxy resins, with minimal material removal and or surface preparation requirements. Infrared thermography has been used to validate the degree of resin infiltration for the repaired sandwich samples. Similarly, the large dry spot defects in CFRP laminates have been well filled, demonstrating a more rapid and reliable repair than current methods.