Digital Image Mechanical Identification (DIMI)

Stéphane Roux (1) , François Hild (1)

1 LMT - Laboratoire de Mécanique et Technologie

A continuous pathway from digital images acquired during a mechanical test to quantitative identification of a constitutive law is presented herein based on displacement field analysis. From images, displacement fields are directly estimated within a finite element framework. From the latter, the application of the equilibrium gap method provides the means for rigidity field evaluation. In the present case, a reconditioned formulation is proposed for a better stability. Last, postulating a specific form of a damage law, a linear system is formed that gives a direct access to the (non-linear) damage growth law in one step. The two last procedures are presented, validated on an artificial case, and applied to the case of a biaxial tension of a composite sample driven up to failure. A quantitative estimate of the quality of the determination is proposed, and in the last application, it is shown that no more than 7% of the displacement field fluctuations are not accounted for by the determined damage law.

Mots clés: Damage model; Digital image correlation; Inverse problem; Photomechanics

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Stéphane Roux, François Hild. Digital Image Mechanical Identification (DIMI). Experimental Mechanics, 2008, 48 (4), pp.495-508. ⟨hal-00200974⟩