Image-based Stress Field Reconstruction in Complex Media
Résumé
In many instances in life, materials around or within us suffer deformation at high rates. This is the case when engineering structures undergo e.g. impact, crash, forming or pulsed welding. Another important area concerns biological tissues injuries. In those contexts, the transience and inhomogeneous aspect of such loadings as well as the strong multi-physic couplings induced by quasi-adiabatic conditions make both: the experimental capture of the mechanical response very challenging and all the potential assumptions regarding the constitutive relation of the deforming material extremely hazardous. To overcome both issues, we demonstrate in the following that experimental full-field measurements of accelerations can be directly used to inverse the local equilibrium equation and reconstruct fields of stress tensor with no assumption at all on the constitutive relation and its potential spatial and temporal variations. It is also demonstrated that both experimental stress and strain fields can be recombined to eventually identify the local tangent stiffness tensor of the material. The latest constitutes a first step in the field of "model identification", as opposed to parameters' model identification.
Domaines
Sciences de l'ingénieur [physics]
Origine : Fichiers produits par l'(les) auteur(s)