Modelling  real  microstructures  from  RX  micro-tomography  images  for  robust  FEM  simulation of coupled multi-physics phenomena

RX  microtomography  has  become  an  essential  technique  for  the  investigation  of  materials behaviour,  particularly  concerning  damage  and  durability  issues.  This  technique  has  been successfully  employed  for  example  to  describe  the  morphology  of  cracks  and  defects  for  several classes of materials (composites, polymers and metal alloys), but has been little used in the context of  the  characterization  of  the  degradation  phenomena  associated  with  exposure  to  aggressive environments, aging and multiphysics couplings. The  Pprime  Institute  in  Poitiers  –  thanks  to  the  recent  acquisition  of  X-ray  micro-tomographic facilities (partly financed by Equipex Gap Program)- has already acquired a number of skills in the use and analysis of these data, especially concerning (area cracked surfaces, lengths of cracks, porosity rate …).

To go further in the use of the segmentation of images and quantitative analysis of the evolution of defects during testing, it is essential  to  build  realistic  finite  element  models  starting  from  microstructures  obtained  by  X-ray micro-tomography  images.  Building  of  such  models  requires  the  development  and  the implementation of a number of advanced tools for segmentation, mesh, and specific numerical skills. This action is expected to provide simulations  of  coupled  thermo-diffuso-mechanical behaviour  in  order  to  clarify  the  effect  of  the  microstructure  of  the  material  on  the  degradation phenomena related to exposure to aggressive environments.