University of Bristol

Supervisors: Dr Sasha Velichko & Dr Rob Hughes

Industrial Partner: NDEvR

The problem of inspection and characterisation of fibre-reinforced composites has significant practical importance in many industrial sectors, including aerospace, automotive, and high value manufacturing industries. However, a complex and heterogeneous structure of composite laminates represent a challenge for imaging and interpretation of measurement results.

One commonly used approach is based on utilising ultrasonic waves, since they offer a good trade-off between penetration, sensitivity, resolution and allow inspection of the entire volume of a component.

Traditional methods of ultrasonic inspection require scanning of a single probe in a pulse-echo regime. Although this approach provides important information, the imaging capabilities are limited and an improvement in resolution, sensitivity and material characterisation accuracy is only possible by exploiting alternative measurement and signal processing techniques.

In recent years the number of applications for ultrasonic phased array inspection has increased dramatically. The development of Full Matrix Capture (FMC) based techniques lead to many advances in defect detection and characterisation. However, there have been much fewer applications of phased array inspection of composite components. Moreover, most of the reported examples used 1D arrays which have limited capabilities in imaging of a general 3D material’s microstructure. The main goal of this project is to explore the potential of using 2D ultrasonic arrays and advanced signal processing methods for microstructural characterisation of composites.

The project will consider the problem of mapping of fibre orientations, which is one of the most critical parameters of composite materials. This goal will be achieved through development of novel signal processing algorithms and extensive experimental trials on variety of material samples.