Composite Aircraft NDE (CAN)
As new materials such as fibre composites and new manufacturing technologies such as additive manufacturing come on-streamare introduced across the industry, new non-destructive evaluation (NDE) methods of inspection for components and assemblies need to be developed to replace more traditional, less efficient inspection, processes.
This three- year, £2.62.7m project was led by Qinetiq in collaboration with University of Southampton, University College London, X-Tek Systems, Axi-Tek and Rolls-Royce plc. The aim was to develop new testing techniques to ensure modern aircraft are designed using the latest materials and techniques to reduce their environmental impact, whilst ensuring their safe operation.
As part of this project, Ttwo technologies were investigated. The first, already being used in border security for the detection of objects such as ceramic knives and drugs, is backscatter x-ray. In contrast to traditional x-ray machines which transmit rays through an object, backscatter xs-ray detects radiation reflected back from an object, forming a 2D-image, highlighting materials that metal detectors and older x-ray machines don’t see. Its other advantage is that it can be used even if only one side of a component is available for examination.
The second technology, laminar CT (computer tomography), is based on medical CT scan methods. Fibre composite structures comprise multi-directional layers of material, making it difficult to detect faults such as voids or microcracks. Through this technology, a set of x-ray projection images is acquired to create an image of the layers, allowing irregularities and defects in the lay up to be detected.
The increased computing speed now available makes the two evaluation technologies more efficient than traditional processes, saving money, supporting the increased production rates demanded but more importantly ensuring parts produced using new manufacturing technologies and materials repeatedly meet quality standards. Laminar CT also has the potential to be used in-field where damage to in-service composite components is not always visible and is harder to detect.Download the Composite Aircraft NDE (CAN) case study