Automatic processing of an orientation map into a finite element mesh that conforms to grain boundaries

Abstract

A new procedure for image-based finite element models of materials is presented. This method is based on a conformal meshing strategy relying on (i) an efficient graph-based community detection algorithm for image segmentation and feature contour extraction as well as (ii) the generation of selectively refined meshes using the Gmsh suite. It provides a versatile and close to automatic environment for meshing complex microstructures. The procedure is illustrated with polycrystal microstructures obtained by orientation imaging microscopy. Hot deformation of a Duplex stainless steel is investigated based on ex-situ EBSD measurements performed on the same region of interest before and after deformation. A finite element mesh representing the initial microstructure is generated and then used in a crystal plasticity simulation of the plane strain compression. Simulation results and experiments are in relatively good agreement, confirming a large potential for such directly coupled experimental and modeling analyses, where the present image-based meshing procedure facilitates the task greatly.