Ultrasonic and Electromagnetic NDT
Guided wave ultrasound has been exploited for NDT in pipes, flexible risers, rails and sheet piles. Collaborative research is being pursued with an industrial partner to investigate propagation of dispersive modes and mode coupling in such structures. Focused beams and time reversal techniques are being exploited to minimise unwanted mode coupling. Advanced digital signal processing techniques are used to improve the resolution of crack detection based on guided wave ultrasonic signals. Research is also carried out to develop an embedded system based on Field Programmable Gate Arrays (FPGA). Recent efforts have also been directed towards the data collection and signal processing of seismic data in order to seek precursors to earthquake activity. A further avenue of research which is currently being pursued is the peizo-electric effect occurring in massive structures. Rocks in the earth's crust when subjected to stress, emit electromagnetic radiation. This can be detected at the earth's surface and research is underway to detect patterns in these emissions and correlate them with seismic activity. The same phenomenon is being exploited in the built environment to provide a non destructive testing approach to building structures.
