Open PhD position: Damage mechanisms in insulating polymer materials under mechanical stress and high voltage : theory and simulations.
We propose a theoretical PhD project for describing damaging mechanisms either under applied electrical field and under applied stress. This is a theoretical work which follows earlier experimental studies on damaging under mechanical stress [Mourglia-Seignobos et al. Macromolecules 2014] and an on-going project regarding damaging under applied electric field. The aim is to identify and describe the damaging mechanisms and to develop a theoretical model for both situations. Currently, we study the microscopic mechanisms under medium to high electric field, in long lifetime regime. Dielectric properties of materials are investigated along electrical fatigue tests, combined with microscopic structural characterization (tomography, Ultra-small angle X-rays scattering, etc…). The methodology we use is similar to the one we used for studying fatigue in semi-crystalline polymers and adapted to the specific considered subject. Based on these works, theoretical model will be implemented into a 3D numerical model allowing to study the nucleation and growth of defects, until final breaking of the material, based on an already existing 3D mechanical model. The model will be compared to experimental results on both electrical and mechanical damage and ultimate failure.
This PhD is proposed within the context of a collaboration between Nexans, a worldwide leading company for electric networking, Solvay and Laboratoire Polymères et Matériaux Avancés (LPMA), within the context of the “Lyon Polymer Science and Engineering” collaborative network. The PhD will take place at LPMA.
This PhD project is suitable for applicants graduated in polymer physics and/or condensed matter physics and/or statistical physics and/or mechanics and material science. To apply please send detailed CV and application statement to:
tel: +33 (0)4 28 27 10 30