PhD Studentship (Sponsored by Lloyds Register Foundation) - Development of methods to evaluate dynamic fracture toughness of metallic materials at very high loading rates under conditions of limited plastic deformation

Background

Many important industrial applications require that dynamic fracture toughness of materials is quantified and the accuracy of safety assessments depends on this material property. The most extreme dynamic loading conditions are encountered in many industrially relevant situations and it is important to understand the response of the material to enable improved design and material qualifications. This study would extend existing fracture toughness measurement practices for quasi-static and medium loading rates to higher loading rates than currently contemplated. The applications resulting include nuclear safety cases, offshore oil and gas accident scenarios and transportation of volatile substances. The large uncertainties encountered with respect to material behaviour at high loading rates often translates to a significant problem for designers and structural integrity engineers when assessing safety, economic and operational implications of structural behaviour. Emphasis on safe operation is set to increase this century for many important industries as the challenges mount to realise unrestricted energy which is fundamental to the provision of civilian services and the development of civil infrastructure. The margins for error will reduce and therefore investment in materials testing methods is paramount to the success of many engineering operations at the front of progress in engineering technology.

Project Outline

Dynamic fracture of experimental laboratory specimens is commonly associated with significant inertial effects manifest as large oscillations within the load- displacement record. These oscillations mask the true deformation path of the material and present particular difficulties when measuring fracture toughness.

This research PhD would develop a new method to analyse dynamic fracture toughness tests obtained using a high loading rate servo-hydraulic test machine. The research would utilise experimental and techniques to establish the behaviour of three point bend specimens under dynamic loading and particularly the crack driving force versus time relationships.

The study will focus on the behaviour of high strength metallic material and the outcome will assess the adequacy of current dynamic fracture toughness measurement procedures in light of the new findings. The research will also provide recommendations to improve test guidance so that more accurate measurements of toughness may be made. This will be of prime importance to applications where the material resistance to crack initiation may be low but the safety margins are of critical importance.

About the Industrial Sponsor

The Lloyd’s Register Foundation funds the advancement of engineer-related education and research and supports work that enhances 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 NSIRC

NSIRC 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 cutting edge research and highly qualified personnel to its key industrial partners.

About the University

Lancaster University is a strong and dynamic university with a very highly regarded Engineering Department. In the 2014 Research Excellence Framework, 91% of research quality and 100% of impact was assessed as being internationally excellent and world leading. Lancaster’s approach to interdisciplinary collaboration means that it has pre-eminent capacity and capability for the integration of Engineering with expertise in the areas of data science, autonomous and learning systems, intelligent automation, materials science and cyber security. The University is developing an ambitious growth plan for Engineering, including investment in staff, doctoral students, equipment and a new building focussed on research themes including Digital and Advanced Manufacturing. Lancaster is the current Times and Sunday Times University of the Year.

Candidate Requirements

Candidates should have a degree at 2.1 minimum in an engineering discipline or materials science/physics. Candidates with relevant graduate work experience within materials, mechanical, civil or structural engineering are especially welcome. Post graduate students with experience in this area of technology are also welcome when evidenced by a qualification and master’s thesis. Overseas applicants should also submit IELTS results (minimum 6.5) if applicable.