EngD student, 2013 intake
Research: Advanced (Electro) Magnetic NDE Techniques for Pipeline Inspection and Monitoring
University: Imperial College London
Sponsoring company: BP plc
Undergraduate Masters in Physics, University of Warwick, June 2013. I was introduced to ultrasonics and the field of NDE via a summer research project in 2012 that explored the fabrication of matching layers for air coupled piezoelectric transducers where I began using FE modelling and ultrasonic theory. My current work, however, focuses on the measurement of weak magnetic fields as a means of NDE.
A significant percentage of pipelines cannot be inspected via traditional in-line inspection using smart pigs due to sharp bends, changes in pipe diameter, and practicality of pig traps. The structural health of these pipelines must still be determined if failures that can lead to huge financial and environmental damage are to be avoided. The focus of the project is to develop a technique that is able to inspect or monitor unpiggable pipelines outside of their insulation coating.
A method is being explored which injects an AC current into the pipe and measures variations in components of the induced magnetic flux density profile surrounding a pipeline in the region local to a defect. As the current changes direction as it flows around a defect, this causes the induced magnetic field profile to change.
Experimental and modelling work is being undertaken in order to characterise the best way to adapt this technique for use in the field.
Figure 1: The axial component of the magnetic flux density plotted at 75 mm lift off from a pipe carrying 2A of surface current. A bowl shaped defect of third wall thickness depth and 3 wall thickness diameter is on the pipe outer surface centred at (0,0), and marked in red.