PhD Studentship - Quantitative Guided Wave Inspection in Complex Tubular Structures
Guided ultrasonic waves are currently used to screen tens of metres of pipeline for corrosion or defects from a single test location. One or more rings of piezoelectric transducers transmit ultrasound into the pipe, which acts as a waveguide for ultrasonic waves. Changes in geometry such as welds, thickness changes, and defects, reflect some of the wave energy back. These reflected signals are received by the transducers, and the analysis of these signals provides valuable information on the state of the pipe which is then used to ensure the safety of continued operation.
In recent years, improvements have been made to guided wave inspection procedures for straight pipes to estimate the size and position of flaws and to focus the sound energy to increase sensitivity. However, the new techniques are only designed for simple geometries with uniform wall thickness and can therefore be ineffective in more complex tubular structures such as those with changes in thickness, attachments or weld cap geometry.
One recent example of the potential for guided wave inspection of complex structures is the inspection of nuclear reactor boiler spines. Standard guided wave inspection procedures were successfully used to detect a flaw beyond multiple changes in wall thickness and attachments. TWI carried out modelling of guided wave propagation in the boiler spine, which was used in conjunction with a series of mock-up trials to correctly predict the size of the defect and to estimate detection capabilities at several locations along the spine. However, there is significant potential to develop new techniques that would improve the detection capability in complex pipe structures by allowing greater sensitivity and more quantitative information to be derived.
TWI has many years of experience in the Finite Element Modelling of guided ultrasonic waves, and works closely with the subsidiary company Plant Integrity Ltd to develop and improve guided wave capabilities. Using Finite Element Analysis (FEA) with the ABAQUS software, the proposed project will develop new signal analysis techniques for focusing and flaw sizing, for the successful inspection of complex pipe geometries.
In this PhD, FE modelling will be used to develop novel techniques for the successful inspection and assessment of complex pipe geometries containing welds, attachments or multiple flaws. Techniques for focusing and/or the prediction of flaw sizes will be investigated through modelling. Experimental validation will be carried out alongside the project, and the experimental and modelling results will be used together in order to achieve improvements to the existing capability in complex pipe.
About the University
The University of Warwick’s School of Engineering is one of the leading engineering schools in the UK, and has a strong research profile. The Centre for Industrial Ultrasonics (CIU) consists of a team of over 30 researchers across the Faculty of Science, led by four highly experienced academics who have run a number of very successful, large scale research projects.
NSIRC is a state-of-the-art postgraduate engineering facility established and managed by structural integrity specialist TWI, working closely with a number of academic and industrial partners. NSIRC aims to deliver cutting edge research and highly qualified personnel to its key industrial partners.
Candidates should have a relevant degree at 2.1 minimum, or an equivalent overseas degree in Mechanical or Civil/Structural Engineering, Material Science, Mathematics, or Physics. Candidates with suitable work experience and strong capacity in numerical modelling and experimental skills are particularly welcome to apply. Overseas applicants should also submit IELTS results (minimum 6.5) if applicable.
This project is funded by TWI and the University of Warwick. The studentship will provide successful Home/EU students with a minimum stipend of £16k/year and will cover the cost of tuition fees. Overseas applicants are welcome to apply, with total funding capped at £24k per year.