PhD opportunities

Damage to fracture transition and 3D numerical modeling of fracture within a large deformation context.

Thesis proposal

Area of expertiseComputational mechanics and Materials
Doctoral SchoolSFA - Sciences Fondamentales et Appliques
SupervisorM. Pierre-Olivier BOUCHARD
Co-supervisorM. Daniel PINO MUOZ
Research unitCentre for material forming
KeywordsDuctile Fracture, damage to fracture transition, finite element, 3D crack propagation
AbstractIn order to address the objectives mentioned above, the expected scientific program is the following:
Improved kill-element technique: This first axis will consist in improving the actual kill element technique by using mesh adaption techniques in order to control the mesh refinement perpendicular to the failure plane. Such technique will allow limiting the volume loss during kill-element and will induce smoother fracture surfaces [4]. Finally, additional mesh smoothing techniques could be applied in order to improve surfaces smoothness.
Damage to fracture transition and crack initiation: Many studies were conducted in the past to predict ductile fracture in Forge [1-3]. Ductile damage models of failure criteria define a damage variable that grows and give raise to failure initiation once a threshold is reached. This damage analysis is based on continuous mechanics and the transition to discontinuous fracture will be addressed here. In particular, the insertion of a discontinuity, representing the crack surfaces, will be handled in a full 3D parallel environment based on continuous damage fields [5, 6].
3D Crack propagation: Once initiated, 3D crack propagation will raise two main challenges that should be addressed: (i) prediction of crack path based on damage fields and (ii) development of advanced remeshing techniques to propagate cracks in the 3D mesh [6-8]. The idea would be to define fracture surfaces by Level-Set functions and to enhance a recently developed body-fitted mesh adaptation technique [9,10] to handle 3D crack propagation in a robust way.

The PhD student will benefit from lectures in materials science, non-linear solid mechanics, damage and fracture. These competences will provide opportunities to develop future activities in various R&D sectors in energy, transport and metallurgical industries.
ProfileDegree: Engineering degree or MSc in Computational Mechanics with excellent academic records.
Skills: Computational Mechanics and applied mathematics with a strong knowledge of the finite element method and programming (C++, Fortran) skills. Non-linear solid mechanics and in particular knowledge in damage and fracture mechanics would be appreciated. Proficiency in English, ability to work within a multi-disciplinary team.
FundingConvention CIFRE