PhD scholarship on: "Reduced Order Model of PGD type application to numerical computing in high cycle fatigue"

saberelarem's picture

A fully funded PhD scholarship exists in the area of solid mechanics at
the Arts et Métiers ParisTech, CER Angers, France. 
http://www.ensam.fr/en/.

The successful applicant will have a  Masters' degree  in
solid mechanics, physics or applied Mathematics . He/she 

is expected to have very good numerical
skills.

contact:  franck.morel@ensam.eu  saber.elarem@ensam.eu  Camille.ROBERT@ensam.eu

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ABSTRAC: Reduced Order Model of PGD type application to numerical computing in high cycle fatigue

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Deadline for application : 04 /06 /2013

 

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In this project, we aim to study the potential contribution of Model Order Reduction methods in modeling the behavior of materials under cyclic loading. Although this project is mainly focused on
numerical aspects, the overall objective is to contribute to the development of a comprehensive methodology that is able to integrate the informations obtained from numerous experimental work
carried out by the PMD team members who have developed in recent years, a strong expertise in the field of fatigue under complex loading of materials and structures. Also, they have established a set of models for damage and life prediction and have at their disposal advanced experimental facilities such as a combined tension-torsion-internal pressure fatigue machine. 

HCF of metallic materials is a failure mode that concerns many components
used in all areas of mechanical engineering. It is characterized by a
low loading level and leads to high number of loading cycles
generally between 10^5 and 10^7.

The consideration of the initiation and propagation of cracks in this
fatigue regime faces many difficulties related to the scale where the
driving mechanisms take place. More precisely, after initiation,
the microcracks spend a significant fraction of the total life to
spread across three or four grains before turningto a different mode
of propagation.

At this scale, the local plasticity, microstructural
heterogeneities, and crystal orientations play a key role in the
damage. Moreover, during the loading, damage evolves over successive
scales until the main crackleading to the failure of the component.

The multi-scale and probabilistic approaches developed in recent years by
the PMD team of LAMPA have yielded quite convincing results on the link
between the microstructural heterogeneities and macroscopic
characteristics of fatigue strength under complex loading. Modeling
has always been coupled with keen observations of local damage
mechanisms.

Although the different scales of damage mechanisms
involved in the initiation processes of fatigue cracks are relatively well identified (grain scale, slip bands ...), numerous works are
still needed to locally access the actual stress and strain fields which are of considerable importance since they are the cause of
initiation and propagation of fatigue microcracks.