Modélisation de la rupture d'un milieu fragile soumis à l'injection d'un fluide visqueux : Analyse de la singularité en pression et du décollement en pointe de fissure

Abstract : The crack evolution under a viscous fluid action is a complex phenomenon where the understanding of the mechanical phenomena near the crack tip is still largely limited. This is the case for the lag between the solid and the fluid front propagation which appears for some configurations of injection rate, fluid viscosity and material toughness. This thesis proposes a simplified model for this strongly coupled interaction problem.The first chapter studies a simplified one-dimensional model of a elastic film bonded to a rigid substrate. We consider a viscous fluid injection between the film and the substrate. The crack propagation is assumed to follow the Griffith's law. The existence of the lag is neglected and a non-linear behavior law is chosen for the viscous fluid. Using an asymptotic analysis, an approximate solution is established for the low viscosity case. It is shown that the pressure field diverges at the crack tip and that the kinetics of the crack is influenced by the injection rate. The second chapter proposes to take into account the existence of the lag by modifying the model formulation and rewriting it as a discrete time optimisation problem where the delamination zones are part of the unknowns of the problem. This formulation is validated for the analytical example of a drop crushed by a rigid bar. It is shown that this formulation and its implementation can manage the evolution of several drops of any shape and correctly captures the drops spreading and coalescence. This formulation is then extended to the case of a drop crushed by an elastic film. In the last chapter, the validity of the lubrication hypothesis is examinated. Using an asymptotic analysis, a regularized Reynolds equation is constructed with higher gradient terms taking into account the spatial variation of the walls height. A comparison between the pressure fields behaviour given by the classical and the regularized Reynolds equation is shown for different conducts.
Complete list of metadatas

Cited literature [47 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-01981751
Contributor : Abes Star <>
Submitted on : Tuesday, January 15, 2019 - 11:28:22 AM
Last modification on : Wednesday, August 21, 2019 - 12:00:31 PM
Long-term archiving on : Tuesday, April 16, 2019 - 1:55:00 PM

File

73684_CORDOVA_HINOJOSA_2018_ar...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01981751, version 1

Collections

Citation

Rogers Bill Cordova Hinojosa. Modélisation de la rupture d'un milieu fragile soumis à l'injection d'un fluide visqueux : Analyse de la singularité en pression et du décollement en pointe de fissure. Mécanique des solides [physics.class-ph]. Université Paris-Saclay, 2018. Français. ⟨NNT : 2018SACLY016⟩. ⟨tel-01981751⟩

Share

Metrics

Record views

76

Files downloads

51