Roderick Smith
Professor
Fellow of Royal Academy of Engineering
Imperial College London, UK
Biography: Roderick Smith is currently Emeritus Professor of Railway Engineering, Imperial College London and Chair of the Future Railway Research Centre. He was Chief Scientific Advisor to the UK Department for Transport from 2012 to May 2014 and 126th President of the Institution of Mechanical Engineers 2011-12. He is President of the Engineering Integrity Society and Director of FESI. He is frequently called as an expert witness in legal cases, particularly in cases involving fatigue. He has published extensively on structural integrity, fatigue, railway engineering and energy and is frequently invited to address international meetings and conferences. He is director of his own consulting company, Roderick A Smith Consulting Engineer and has advised on many engineering issues throughout the world. He has been awarded honorary degrees from the Universities of Sheffield and Lincoln and is an Honorary Fellow of Queens’ College Cambridge. He is a fellow of Royal Academy of Engineering.
Invited Lecture: Fatigue: still an intractable problem - A review of outstanding issues
Abstract: Experimental studies of fatigue started long ago with the failure of railway axles in the 1840’s. Empirical rules were discovered, the fatigue limit in steels being particularly useful. The early 1950’s saw the investigations into the Comet failures and the beginnings of quantitative fracture mechanics and the study of crack propagation. The past 50 years have seen a huge increase in materials research and in fatigue research in particular. This has been assisted by enormous increases and availability of cheap computing power, remarkable improvements in our ability to measure real service environments, the development of electron microscopy and the technical ability to match service conditions with those in the laboratory. In this same period, my own career has developed away from laboratory-based research of fundamentals into involvement in many failure investigations in a wide range of industries, including shipping and railways. But these and other industries are now being subjected to changing pressures, including climate change and the effects of extreme weather events on resilience, the need to reduce carbon emissions and light-weighting of structure. Failures can range from the super critical, such as the recent loss of a fan blade on a Boeing 777 near Denver to the trivial such as knobs and small parts on domestic equipment. These and many other apparently diverse structural failures have many common features. Principal amongst these are the frequent lack of definition of the stresses to which critical parts are subjected, the interactions of several failure modes, typically fatigue, corrosion and wear and the difficulty associated with monitoring developing deterioration by non-destructive examination. Surprisingly, lack of appreciation of stress concentrating features of design and local stresses near joints is still widespread. This lecture will illustrate why failures still occur despite the explosion in publications on fatigue in recent years. Too much research overextends its applicability by extrapolating from a limited data set and fails to recognise the scatter inherent in fatigue, together with lack of strict similitude between test and application.
