NSIRC Coded Excitation Methodologies For UT Techniques Exhibiting Poor Signal To Noise Performance

NSIRC Coded Excitation Methodologies For UT Techniques Exhibiting Poor Signal To Noise Performance  

Background 

Non-destructive testing (NDT) forms a critical step in the design, manufacture and through life servicing and maintenance of structurally significant assets throughout industry. One of the most used NDT methods is ultrasonic testing (UT), due to its ability to perform full volume inspection of the asset. 

Codes and standards typically dictate that a water or oil based couplant is used to enable efficient transfer of energy from the ultrasonic transducer to the structure under inspection to maximise signal to noise. However the application and removal of couplant can be a time consuming process and there are a number of industrial applications where use of couplant may be prohibited, preventing the use of ultrasonic testing. 

These project proposes development of novel ultrasonic array data acquisition and signal processing techniques to restore signal to noise during inspection, degraded due to dry coupled (no use of couplant) ultrasonic inspection. Successful development and implementation of a dry coupled ultrasonic inspection system is considered a disruptive technology, which will fundamentally change the way UT is performed and the range of applications it is applicable to, ultimately leading to increased safety and fitness for service assessments for industry. 

Project Outline 

The successful candidate will be primarily located at TWI state of the art NDT research and development facility in Port Talbot, South Wales, UK. 

Industrial ultrasonic testing systems primarily utilise resonant transducers stimulated by a short square wave pulse to generate a short Gaussian type ultrasonic wavelet in the test structure under inspection. This project proposes investigation into the use of coded excitation signal forms (e.g. chirp signals) in order to increase the transmitted energy with the aim to restoring some of the signal loss at the transducer/test component interface when couplant is omitted from the inspection setup. This coded data acquisition strategy has become possible on a commercial level in recent due to inclusion of arbitrary wave form generators in a select number of ultrasonic pulser-receiver hardware systems. As well as experimental data acquisition it is anticipated that wave form optimisation will be underpinned though the use a simulation software using algorithms to be developed within the scope of the software. 

The successful candidate shall work alongside industrial and academic teams to achieve their objectives. As part of the dry coupled programme, investigations shall be undertaken to optimise the transducer wedge material, used to transmit energy into the test component. While the successful candidate will have involvement with these activities, in particular any research and development aspects, this is considered a secondary activity to the data acquisition and signal processing elements of the project. 

Candidate Entry Requirements 

Candidates should have (or be on target to achieve within the next 12 months) a degree at 2.1 minimum in maths, physics or relevant Engineering discipline, or an equivalent overseas degree in relevant subjects. Overseas applicants should also submit IELTS results (minimum 6.5) if applicable. 

Funding Notes 

This project is funded by Lloyd’s Register Foundation (LRF), TWI and University of Strathclyde. 

The studentship will provide a successful student with a tax-free bursary stipend of £23,000 – £26,000 per year for 3 years and will cover the cost of tuition fees. PhD registration is at the University of Strathclyde. 

About Industrial Sponsor 

The Lloyd’s Register Foundation funds the advancement of engineering-related education and research and supports work that enhances the safety of life at sea, on land and in the air, because life matters. Lloyd’s Register Foundation is partly funded by the profits of their trading arm Lloyd’s Register Group Limited, a global engineering, technical and business services organisation. 

About University/Department 

The University of Strathclyde Faculty of Engineering at the is one of the largest and most successful engineering faculties in the UK, and the largest in Scotland. As a leading international technological university, Strathclyde University is recognised for its world class research, knowledge exchange and educational programmes.  

About NSIRC | TWI 

The National Structural Integrity Research Centre is a state-of-the-art postgraduate engineering facility established and managed by structural integrity specialist TWI. Working closely with top UK and International Universities and a number of leading industrial partners, NSIRC aims to deliver industry led and relevant cutting edge research and highly qualified personnel to its key industrial partners. 

TWI Technology Centre (Wales) specialises in the development and application of state-of-the-art non-destructive testing (NDT) methods. Through applied research and development in response to requests for assistance from member companies, we provide real-world solutions to inspection challenges across a broad range of industries.