PhD defence by Elena Bossolini, Friday 8 December 2017 at 13:00, DTU Kgs. Lyngby, Building 308, Auditorium 11.
Supervisor:
Professor Morten Brøns
Co-supervisor:
Associate Professor Kristian Uldall Kristiansen
Examiners:
Associate Professor Christian Henriksen, DTU Compute
Professor John Hogan, University of Bristol
Professor Peter Szmolyan, Technische Universität Wien
Chairman:
Associate Professor David Brander, DTU Compute
Popular science summary:
Friction plays a crucial role in our everyday life. It is a key way of loosing energy in mechanical systems, and it also induces natural phenomena such as earthquake faulting. It is important to understand the mechanisms of friction, but despite all the experimental and theoretical efforts, there is still no comprehensive understanding of it, and no universal friction model exists. Nevertheless, it is recognised that friction is a force resulting from multiple processes, and that it acts on different scales. Considering earthquake faulting, an earthquake rupture is a fast phenomenon that can last up to minutes, but the time of inactivity between an earthquake and the following one can last up to millennia. Furthermore, the action of friction is generally explained as the loss and restoration of linkages between the surface asperities at the molecular scale. However, the consequences of friction are noticeable at much larger scales, like hundreds of kilometers in the case of earthquake faulting.
Because of the great variation in time and spatial scales, direct numerical simulations of problems with friction are almost intractable, and a mathematical approach is needed. In this PhD project, we do a rigorous mathematical analysis of two mechanical problems with friction. By applying new analytical methods, we obtain a new insight into the two problems. This insight is a foundation for the mathematical study of more complicated and realistic friction problems. Furthermore, it can help the geophysical community into developing better experiments for rock friction. Finally, the research has led to a method that can help in simulating more efficiently mechanical problems with friction.
Read more about this thesis in DTU Orbit.
Everyone is welcome.