Acoustic Emission Characterisation of Composite Damage

Project Title:

Acoustic Emission Characterisation of Composite Damage


Professor Steve Wilcox

Contact person and email address:

Steve Wilcox

A brief description of the project:

The new generation of civil transport aircraft uses composites as primary structural material due to its high strength-to-weight ratio and other design benefits. The construction of CFRP composite materials consist of phases with each of these phases exhibiting distinct failure mechanisms. Many parameters affect the failure mode of composite materials, such as, the interface between the fibre and the resin, the ply stacking sequence, environmental conditions, manufacturing process. Failures can occur either in the fibre, matrix or at the interface between the matrix and the composite. Recent advancements in sensor sensitivity and capability, capacity of data acquisition cards, and modern signal processing methods have made Acoustic emission (AE) a good choice for in situ inspection. AE is a phenomenon that results from high frequency stress waves that are generated by a rapid release of energy within a material by sources such as crack initiation or growth. AE is fundamentally different from other non-destructive testing (NDT) methods in that it relies on the signals originating from within the structure rather than outside it [6,7]. The gathered monitoring data can be used to detect flaws before they become critical to the safety of the structure. Applying a mechanical load to a composite material can result in many types of damage; debonding between reinforcement and the matrix material, matrix cracking, failure of the reinforcement and delamination in the case of layered composites. AE is a suitable monitoring technique capable of detecting these damage types in composites.