Centre National De La Recherche Scientifique

Ecole Normale Superieure De Cachan

Electricite De France

Association Pour La Recherche Et Le Developpement Des Methodes Et Processus Industriels (a.r.m.i.n.e.s.)

Ecole Normale Superieure Paris-saclay

François Hild

Stéphane Roux

Hugo Leclerc

Qiwei Shi

Félix Latourte

Thilo Morgeneyer

Ante Buljac

The invention relates to a method for processing images obtained by a diffraction detector, of a crystalline or polycrystalline material, in which a first image of the material is acquired in a state of reference as well as a second image of the material in a deformed state. The invention is characterised in that, in a calculator, during a first step (E, E), a current elastic deformation gradient tensor Fis given a value determined by calculation, during a second step (E), the current displacement field induced by the tensor Fis calculated, during a third step (E), third digital values of a deformed image {hacek over (g)}(x)=g(x+u(x)) corrected by the current displacement field are calculated, and during an iterative algorithm, iterations of the second and third steps (E, E, E) are carried out on modified values of the tensor r Funtil a convergence criterion is met in relation to the correction to the current value of F.

Method, device and program for processing diffraction images of a crystalline material

A computer-implemented method for identifying mechanical parameters of an object subjected to mechanical stress is provided. The method comprises a step of acquiring, by an imaging means, images of the object taken before and during the application of the mechanical stress, three steps of calculating the effects due to the stress carried out either on the basis of the modeling of the recorded images or on the basis of a theoretical mechanical modeling of the stress, a step of defining a functional equal to the difference between the two models and a last step of minimizing said functional so that the experimental model is as close as possible to the theoretical mechanical model. Additional measurements make it possible to refine the method.

Computer-implemented method for identifying mechanical properties by coupled correlation of images and mechanical modelling

A tomography scanner includes at least one first emission source (GX), one first matrix detector (D), and a computer (C) arranged to produce an initial tomography of an object (E) based on radiographs arising from the first matrix detector, taken from various angles. The tomography scanner further includes a second emission source (GX) and a second matrix detector (D) arranged so that, when the object is subjected to a loading that is known at a given instant in time, the computer determines the changes in the object subjected to said loading based only on the information from the first radiograph of the object under loading arising from the first matrix detector, from the second radiograph of the object under loading arising from the second matrix detector and the initial tomograph, the first radiograph and the second radiograph being taken simultaneously at the same given instant in time.

'4D' dynamic tomography system

In the field of methods of three-dimensional measurement of an object by stereo-correlation, methods require at least two cameras connected to image processing means. These methods include at least a first step of calibration of the two image planes and a second step of spatial matching between these two image planes. These two steps can be followed by a third step of temporal matching. The method provided requires objects, the surface of which has a parametric representation, i.e. a mathematical representation of the object surface having the form of a decomposition over a scalar function basis. The parametric representation is implemented during the first calibration step and/or during the second and third steps of spatial or temporal matching.

Method of three-dimensional measurements by stereo-correlation using a parametric representation of the measured object

Growing community of inventors

Chatenay-Malabry, France

François Hild