Tue, 02 April, 2019
TWI Technology Fellow, Isabel Hadley is due to speak at an upcoming IMechE seminar on ‘Improving Safety with Advanced Fracture Mechanics.’ She will offer an insight into how codes and standards for this area are updated, with particular reference to BS 7910:2019, the latest guide to methods for assessing the acceptability of flaws in metallic structures.
Speaking on her upcoming presentation, Isabel explained that she will demonstrate, “why and how we are changing BS 7910 yet again, and what improvements the users can expect to see.”
Ahead of her presentation, Isabel also took some time to talk about her role at TWI, the challenges of using fracture mechanics in today’s market, and upcoming developments in this field.
Isabel began by discussing her role and involvement with advanced fracture mechanics, explaining, “Over the last quarter-century, I have applied advanced fracture mechanics concepts to pressure vessels, pressure piping, pipelines, bridges, storage tanks, aerospace components, offshore structures and steel buildings, either as part of the design process, or to assess a structure already in service for overall safety or life extension,” adding, “I’m also deeply involved in the development and maintenance of codes and standards to ensure that these assessments are carried out in a safe and reproducible manner.”
With her decades of experience in this area, Isabel is perfectly placed to speak on the associated challenges, noting that “quantifying the results of a fracture mechanics assessment” provided the biggest hurdle. She elaborated, “Whilst there is a vast amount of evidence that the methods we use are safe when applied appropriately, there are a lot of simplifications embedded in them, which mean that it’s difficult to quantify the safety margin or probability of failure associated with a particular assessment. There is an increasing wish to do so, using probabilistic fracture mechanics methods, but considerable challenges associated with doing so.”
However, there are ongoing developments, including the application of probabilistic techniques and an improving understanding of how residual welding stresses can contribute to failure. Isabel noted, “Ultimately, we can expect to see more quantitative assessments, in which engineering risk can be evaluated from an understanding of both the probability of failure and the consequences of failure.”
While these advances are notable, Isabel revealed her own ideas of the fracture mechanics developments we may see over the next 5 years, saying, “I’d expect to see the application of these techniques to non-traditional processes (for example additive manufacture) and materials (e.g. non-metallics), in tandem with advances in inspection technology.”
While Isabel is keen to hear all of the topics to be discussed at the upcoming seminar, she said that the themes of ageing assets, welding residual stresses, sour service and R6 developments are all particularly relevant to her current work.
The seminar itself, which is to be held on 15 May, 2019, at IMechE’s London offices, will allow professionals the chance to discuss and learn about the latest advances.
Isabel will be joined at the event by experts from the University of Cambridge, EDF Energy Nuclear Generation, University of Bristol, University of Manchester, DNV GL, and the Wood Group. TWI’s Principal Project Leader and Materials Engineer, Mike Dodge, will also give a talk to provide his expertise on hydrogen embrittlement of subsea dissimilar metal welds.
See here for more about TWI’s fracture and mechanical testing facilities.
Finally, you can see a webinar Isabel held on BS 7910 here.