Nothing is certain: understanding randomness, uncertainty and unpredictability
A group of researchers spanning academia and industry are studying uncertainty in structures, systems and processes, led by Professor Keith Worden of the Department of Mechanical Engineering at the University of Sheffield. The team: Professor Worden, Dr Graeme Manson, Dr Jem Rongong, Dr Neil Sims and Dr Jen Rowson, have been awarded a prestigious EPSRC Platform Grant in order to carry out their programme of research.
Modern engineering is relying increasingly on computer simulations and modelling for a wide range of processes over the life cycle of products and structures, for example aircraft, buildings and bridges. Because of the expense of making prototypes for testing, the modelling approach offers clear economic advantages. Professor Worden and the team are investigating how to identify and quantify uncertainty within structures, systems and processes by developing sophisticated computational models.
Research under the Platform Grant improves our understanding of a number of issues concerning modelling under uncertainty. "There are several strands to the research, but perhaps most importantly we look at models of systems with uncertainty in their inputs, and seek to determine the reliability of the predictions, in terms of how that system will perform" explains Professor Worden.
The project is a pioneering collaboration, guided by a steering group formed from other experts from academia (the universities of Strathclyde, Southampton and Cambridge) and industry (including Rolls-Royce, Qinetiq and British Aerospace). A highly unusual aspect of the research is that it involves a 'roving reporter'. Postdoctoral researcher Daley Chetwynd´s role is to visit universities and companies abroad where he shares knowledge and technologies developed or implemented at the University of Sheffield. He then returns to Sheffield with the new knowledge and technologies he has acquired and contributed to whilst on secondment. A key member of the team with a non-traditional academic background is computer programmer Andrew Spencer who is using skills developed over three decades of authoring computer games in order to provide the group with sophisticated modelling and visualisation tools.
Exploring Uncertainty
In the context of the programme the term 'uncertainty' is usually understood to mean a lack of knowledge. This may be due to the inherent randomness of nature or may be a result of not completely understanding the exact science of the problem.
A good example of uncertainty within a system comes from the team's work on modelling heart valves, which open and close according to a process of 'pressure loading' generated by blood flow. The behaviour of tissues within the body depends on their material properties, which vary considerably between people and hence are marked by a high degree of uncertainty. By developing a computer model, under the supervision of Drs Jen Rowson and Alaster Yoxall (of Sheffield Hallam University), PhD Student Will Becker was able to make more robust predictions about the likely behaviour of the heart-valve, by identifying the uncertainties responsible for making predictions difficult. This work was also guided by expert statistician Dr Jeremy Oakley from the University´s Department of Mathematics and Statistics.
Another strand of the research has focused on Shaken Baby Syndrome. Researcher Dr Dave Batterbee has studied data from known cases and is working to develop a model of the infant brain/skull system. He will then run computer simulations to determine what happens when a baby is shaken, and the health implications that result. Another related study, a collaboration with the University of Strathclyde, is focusing on developing autonomous robotic devices to inspect buildings and structures for problems such as fatigue and cracks.
Research Outputs
The fundamental science and engineering work behind the project has already produced several commercial applications. Drs Jem Rongong and Chian Wong of the research team are currently extending our understanding of a new technology relating to 'particle dampers' that can suppress vibrations in structures even at high temperatures; patented developments at Sheffield have led to their use by Rolls-Royce in one of their Trent engines. Similarly Dave Batterbee and Neil Sims of the research group at Sheffield are setting up a spin-off company to develop smart mountain-bike dampers which can adapt to any terrain. This work has also been supported by proof-of-concept awards from the University and from Yorkshire Forward.
Drawing upon the existing research excellence within the Faculty of Engineering at the University of Sheffield, the project is anticipated to continue its rich vein of successes; as Professor Worden explains: "The project will lead to applications in many areas, including aerospace, construction, manufacturing, medicine and the environment".
For further information, please contact Ian Kingsbury:
tel: 0114 222 1456
email : i.r.kingsbury@sheffield.ac.uk
Note: Professor Worden will be delivering a talk on 'Ideas of Chaos, Randomness, Uncertainty and Unpredictability of Nature' on Monday 6th April 2009. For more details, please see the Café Scientifique website. This research was funded by the Engineering and Physical Sciences Research Council (EPSRC), one of the UK Government's 7 Research Councils.