Centre puts NDT techniques under the microscope

A TWI (The Welding Institute) product story

Edited by the Engineeringtalk editorial team Aug 9, 2005

A powerful new resource opening in Port Talbot aims to reduce the risk of failure in manufactured products and structures from bridges to aeroplanes to heart pacemakers.

A powerful new resource opening in Port Talbot aims to reduce the risk of failure in manufactured products and structures from bridges to aeroplanes to heart pacemakers.

It will provide vital information on the sensitivity and effectiveness of the sometimes sophisticated tests used to check that complete products or their component parts are free of manufacturing or materials faults before they go into service or during operation.

TWI and the Swansea Institute have established the NDT Validation Centre to assess the accuracy and consistency of the nondestructive testing (NDT) methods used in manufacturing and construction industries.

The DTI, the Knowledge Exploitation Fund (KEF) and industry have given financial support.

The NDT Validation Centre is sited at TWI Technology Centre (Wales) and complements work on research and development of techniques, and training and certification of operatives carried out by TWI.

The collaboration between TWI and Swansea Institute gives the NDT Validation Centre direct input from leading technical experts and academics, access to state-of-the-art equipment, and the opportunity to form multidisciplinary teams quickly to address any NDT problem.

Companies in Wales and throughout the UK can use its services to help maintain their position in the global marketplace.

Fortunately they are rare, but high profile accidents when offshore oil platforms collapse or aircraft engines fly apart make us all aware that defects can be present in structures and can have catastrophic consequences.

This has driven engineers to develop a battery of tests to search for defects whilst keeping the components in service or available for future service, hence the term nondestructive testing.

These tests are not foolproof.

Recent studies have shown significant variability in the effectiveness of manual NDT techniques, implying that defects may not always be found.

There is a clear need to verify and improve the accuracy of detection to increase the confidence of manufacturers, regulators and users alike.

Test methods used in industry to detect defects may employ X-rays, ultrasound, laser light, magnetic or electric fields, and crack-revealing dyes and powders.

The Port Talbot facility will be fully equipped with a wide range of standard and advanced NDT equipment, including: phased array ultrasonics; long range guided wave ultrasonics; digital radiography; computed X-ray tomography; automated NDT; laser shearography; and infra-red thermography.

The centre will provide independent validation of NDT methods across a range of industries.

Typically, the work undertaken by the centre will involve inspecting and testing structures and components, analysing defects and comparing what is found by the test with the defects actually present.

This work will allow engineers to predict component lifetimes and potential for life extension, and ensure that vehicles, products and structures remain safe for use during their lifetime.

The centre will study all materials, NDT technologies and applications, but a key activity will be development and validation of inspection techniques for composite materials through its NCN Composite Validation Group.

The centre will be an integral part of the National Composites Network - a Knowledge Transfer Network, also funded by the DTI and managed by TWI - which facilitates knowledge sharing, networking and technology transfer.

Inspection of composite materials requires significant research, but successful development and validation of appropriate techniques will have tremendous benefits for industries keen to make use of composites in everyday production.