Three-dimensional numerical modeling of ductile fracture mechanisms at the microscale

Abstract : The present PhD thesis aims at a better understanding and modeling of ductile fracture during the forming of metallic materials. These materials are typically formed using series of thermomechanical loads where many parameters such as loading type and direction vary. Predictive numerical tools are necessary to model fracture mechanisms, and then optimize production costs.Ductile fracture in metallic materials is the result of a progressive deterioration of their load carrying capacity due to the nucleation, growth, and coalescence of microscopic voids. In this work, a micromechanical approach is developed in order to conduct realistic full field finite element simulations of ductile fracture at the microscale. Meshing and remeshing methods relying on the use of Level-Set functions are proposed to discretize the microstructure. Thanks to these methods, the geometric properties of Level-Set functions are preserved, as well as the volume and morphology of each component of the microstructure, even at large plastic strains. These numerical methods are extended to account for cracks and model the failure of some components of the microstructure, or interfaces between them. A new contact detection method based on mesh adaptation is also developed.The interest of these numerical developments and micromechanical models is first demonstrated at the scale of representative volume elements with statistically generated microstructures. Then, a new methodology is proposed to conduct simulations of real microstructures observed via in-situ X-ray laminography, with boundary conditions that are measured using digital volume correlation techniques.
Complete list of metadatas

https://pastel.archives-ouvertes.fr/tel-01744733
Contributor : Abes Star <>
Submitted on : Tuesday, March 27, 2018 - 3:57:12 PM
Last modification on : Wednesday, May 15, 2019 - 4:16:06 PM
Long-term archiving on: Thursday, September 13, 2018 - 9:36:46 AM

File

2016PSLEM049_archivage.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01744733, version 1

Citation

Modesar Shakoor. Three-dimensional numerical modeling of ductile fracture mechanisms at the microscale. Mechanics of materials [physics.class-ph]. PSL Research University, 2016. English. ⟨NNT : 2016PSLEM049⟩. ⟨tel-01744733⟩

Share

Metrics

Record views

397

Files downloads

181