DIC identification and X-FEM simulation of fatigue crack growth based on the Williams’ series

C. Roux-Langlois (1) , A. Gravouil (1, 2) , M.-C. Baietto (3) , Julien Réthoré (1) , F. Mathieu (4) , François Hild (4) , Stéphane Roux (4)

1 LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
2 IUF - Institut universitaire de France
3 MIMESIS - Mécanique Multiéchelle pour les solides
4 LMT - Laboratoire de Mécanique et Technologie

A unified Digital Image Correlation (DIC)/eXtended Finite Element Method (X-FEM) framework based on the Williams’ series for fatigue crack growth identification and simulation is proposed. Williams’ series are used for post-processing the displacement measured by digital image correlation. It gives access to the change of stress intensity factors and crack length with the number of cycles. A Paris’ crack propagation law is subsequently identified and further validated by simulating the experiment. The simulation uses measured displacements as Dirichlet boundary conditions and a direct estimation of stress intensity factors based on a coupling between a finite element model and the analytical Williams’ solutions. It is shown that the use of actual boundary conditions is crucial. The use of the Williams’ formalism is further investigated on an elasto-plastic simulation to validate the extraction of nonlinear features in the crack tip vicinity.

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

C. Roux-Langlois, A. Gravouil, M.-C. Baietto, Julien Réthoré, F. Mathieu, et al.. DIC identification and X-FEM simulation of fatigue crack growth based on the Williams’ series. International Journal of Solids and Structures, 2015, 53, pp.38-47. ⟨10.1016/j.ijsolstr.2014.10.026⟩. ⟨hal-01710062⟩