Inspection and Monitoring
The group works on a variety of non-destructive testing and structural health monitoring methods, particularly focusing on ultrasound and guided ultrasonic waves
Electromagnetic methods are widely used in industry but there is considerable scope for improvement. We are involved in several projects in this area in collaboration with Professor Peter Nagy of University of Cincinnati who is a Visiting professor at Imperial.
Current Electromagnetic Methods Projects:
Guided Ultrasonic Waves
The group is particularly well known for the development of long range guided wave inspection. This is used worldwide, particularly in the petrochemical industry and seven PhD graduates from the group work in the spin-out company Guided Ultrasonics Ltd that was formed to exploit the technology. Guided wave inspection is still a very active research area in the group with particular emphasis on applications to the monitoring of complex structures and improved defect sizing methods.
Current Guided Ultrasonic Wave Projects:
Conventional non-destructive testing methods often involve scanning a transducer over the surface of a structure which is time consuming and expensive, and is difficult on complex structures. We are interested in a family of vibro-enhanced methods that potentially overcome these problems, and also in the potential of digital image correlation for inspection and monitoring applications.
Permanently Installed Monitoring Systems
There are many measurements that are not suitable for periodic NDE because the measurement is sensitive to defects, but is equally or more sensitive to other factors that vary in an uncontrolled way across the structure, so leading to missed defects and an unacceptable false call rate; permanent attachment at a fixed position means that, provided the other factors are constant with time, changes in signal give a reliable indication of damage growth. This potentially gives excellent sensitivity to defect initiation and growth, without excessive false call issues, and opens the door to the solution of currently intractable inspection problems.
Current Permanently Installed Monitoring Systems Projects:
Bulk wave ultrasound remains the most commonly used non-destructive testing method. The use of array transducers opens many new possibilities for improving the sensitivity and coverage obtained and in increasing reliability; the group has several projects in this area. The increasing power of computers means that it is now possible to model the propagation of ultrasound and its interaction with defects and so to help with the design and validation of inspections; we have a variety of projects on these topics.