Physical chemistry of friction and fracture: how heat impacts mechanical instabilities
About the job
There is an open PhD position at the University of Strasbourg, ITES Institut Terre et Environnement de Strasbourg, UMR7063 CNRS / University of Strasbourg / ENGEES. This thesis is fully funded by the ANR HotTips, a collaboration between the University of Strasbourg (ITES), the Laboratoire de Physique de l’ENS de Lyon, the Institut Lumière Matière of the University of Lyon I, the SPHYNX group of CEA Saclay, and the Porous Media Laboratory center of excellence, Njord, Institute of Physics of the University of Oslo (Norway).
This PhD thesis will be carried out in the team Geophysics, Imagery and Processes, under the direction of Renaud Toussaint (Director of Research, CNRS), and cosupervision by Alain Cochard (Associate Prof, University of Strasbourg, ITES), Stéphane Santucci (Director of Research CNRS, Laboratoire de Physique – Ecole Normale Supérieure de Lyon), and KJ Maloy, Professor of Physics, University of Oslo, in collaboration with the other partners. A joint supervision (cotutelle) with the University of Oslo is possible.
The offer indicates a deadline on August 23rd 2023 but will be prolongated until Sep 15th 2023.
Description of the thesis
Like the propagation of fractures, the sliding on seismogenic faults takes place in disordered environments, where asperities induce slowdowns and accelerations. In models and experiments, it has been shown that fracture mechanics are dependent on both the fracture toughness distributions of the heterogeneities in the path of the fracture , and the thermal fluctuations that allow the fracture to cross these heterogeneities . Taking into account these two types of disorder, material and thermal, makes it possible to account for many aspects of interfacial fracture dynamics, in the statistics of events, and in fast and slow (aseismic) dynamics [3,4,5]. In an open fracture geometry (mode I), it has been demonstrated that the release of energy by the Joule effect at the crack tip can play a major role in the transition from slow fracture (in the sub-critical creep regime) to rapid fracture: in some cases, very localized heating considerably accelerates the fracture reaction at the molecular scale, the source of macroscopic fracture behavior.
Taking these effects into account helps explain phenomena such as fractoluminescence in the peeling of adhesive tapes, and the load curve linking energy release rate G and rupture speed v in this material, or in the rupture of PMMA . In this context, the transition from a slow strain rate to a fast rupture rate corresponds to a first-order phase transition
Application deadline: 15.09.2023
Contract period: 3 years
The offer indicates a deadline on August 23rd 2023 but will be prolongated until Sep 15th 2023. Offer description and possibility to apply here: