Nicolò Grilli
University of Oxford
2020
Abaqus Mesh and Grain Orientation from EBSD using MTEX
The MTEX Matlab package is used to convert EBSD data to Abaqus input file
Please see the following link for the original code: http://latmarat.net/blog/ebsd2abaqus/
I have added the following feature: adding rotation matrix for each grain of a polycrystal as constants for the corresponding user materials
Usage: Open MTEX and launch: import EBSD data import a .ctf file with the EBSD data set x and y axis according to the convention of your sample and instrument import the variable "ebsd" in the workspace
EBSD data can be filtered, non-indexed regions can be removed
clean4fem function identifies the grains
reduce function reduces the size of EBSD map and leads to a coarser mesh in Abaqus
ebsd2abaqusEuler.m generates an Abaqus input file with one material for each grain in a polycrystal the user materials contain 10 constants, the last 9 constants are the components of the rotation matrix for each grain, transforming a vector from the crystal reference frame to the sample reference frame (Abaqus xyz coordinates)
The three Euler angles of each grain are found by using the following commands from MTEX: grainsReconstructed(ii).meanOrientation.phi1; grainsReconstructed(ii).meanOrientation.Phi; grainsReconstructed(ii).meanOrientation.phi2;
The Matlab script: AbaqusTitanium.m contains an example of EBSD data processing leading to Abaqus input file with reduced number of elements, non-indexed regions removed and clean grain boundaries
Open Abaqus CAE: import > Model and select the input file ebsd.inp generated by the function ebsd2abaqusEuler.m Assembly must be defined Boundary conditions must be defined Generate input file and run Abaqus simulation
See the following paper for an application example: Nicolò Grilli, Philip Earp, Alan C.F. Cocks, James Marrow, Edmund Tarleton Characterisation of slip and twin activity using digital image correlation and crystal plasticity finite element simulation: Application to orthorhombic α-uranium Journal of the Mechanics and Physics of Solids 135 (2020) 103800