To mitigate these risks and facilitate the transition to a hydrogen-based energy economy, global collaboration between academia, industry, and regulatory bodies is essential. Establishing standardized training programs, qualification frameworks, and research initiatives in hydrogen pipeline engineering will be critical in addressing these challenges. A proactive approach in competency development will not only ensure the safe and efficient operation of hydrogen pipelines but also prevent costly failures and accelerate the transition to sustainable energy solutions.
Excursion: A personal journey into fracture mechanics: Closing the circle from theory to hydrogen pipeline design
My first serious exposure to fracture mechanics and fatigue analysis came in 1997, during my Master’s degree, when I enrolled in a course titled Fracture Mechanics and Fatigue. At the time, I was already well-versed in elasticity, plasticity, plate and shell theory, and finite element analysis. However, fracture mechanics – particularly the assessment of structures containing cracks – presented a fundamentally different perspective.
What truly challenged my thinking was when the professor explained that fracture mechanics could be used proactively in the design of structures. This was a radical idea to us as students. Until then, our understanding had been grounded in the assumption that structures should be defect-free by design. The notion that no structure is truly without flaws – and that it is both practical and necessary to design for the presence of cracks – was unfamiliar and, frankly, counterintuitive.
At that time, only a few industries, such as aerospace and high-pressure equipment manufacturing, applied fracture mechanics principles in their design processes. In the pipeline industry, the use of fracture mechanics was limited and specialized. Techniques such as the Maxey equation had been developed specifically for pipelines, but even those were typically reserved for integrity assessments, not design. The general fracture mechanics frameworks outlined in standards like BS 7910 or API 579-1 were not widely adopted in pipeline engineering.
This paradigm began to shift with the emergence of hydrogen as a critical element in energy infrastructure. The introduction of hydrogen pipelines exposed the limitations of conventional integrity assessment methods. Traditional toughness tests like Charpy impact testing were no longer sufficient or valid for these applications. Moreover, the lack of full-scale test data meant the industry could no longer rely on established, pipeline-specific fracture mechanics models. As a result, we had to turn to the broader and more rigorous methodologies outlined in standards such as BS 7910 and API 579-1.
After nearly two decades of applying fracture mechanics solely for integrity assessments, I encountered a hydrogen pipeline design project that brought everything full circle. It was then that I realized the vision introduced to me in that 1997 course – using fracture mechanics as a design tool – was becoming a reality. Since that moment, I have fully embraced the approach and have conducted ongoing research into its applicability to hydrogen pipelines.
Continued innovation and adaption to new and emerging challenges
In conclusion, the evolution of pipeline design and assessment from simple stress-based methodologies to advanced fatigue and fracture mechanics-based approaches reflects the industry’s need to adapt to new and emerging challenges. The advent of hydrogen as an energy carrier underscores the necessity for continued innovation, rigorous material testing, and interdisciplinary collaboration to ensure the reliability and safety of next-generation pipeline infrastructure.