4th International Congress on 3D Materials Science (3DMS) 2018: Measuring and Predicting Grain Shapes, Sizes, Crystallography, and Spatial Distributions III
Program Organizers: Hugh Simons, Denmark Technical University; Henning Poulsen, Denmark Technical University; David Rowenhorst, Naval Research Laboratory; Peter Voorhees, Northwestern University; Satoshi Hata, Kyushu Univ; McLean Echlin, UC Santa Barbara

Wednesday 1:30 PM
June 13, 2018
Room: Store Scene
Location: Kulturvęrftet (Culture Yard) Conference Center

Session Chair: Phil Cook, ESRF

1:30 PM  Invited
3D Modeling and Simulations of Morphologies in Filler-filled Rubbers: Katsumi Hagita1; 1National Defense Academy
    Filler-filled rubber is of great interest as a system in which the 3D structure of fillers in a volume from nanometer to micrometer dimensions greatly influences the structure-property relationships. For tire rubbers, primary shape of the filler can be regarded as a sphere whose diameter is a few ten nanometer. Morphologies of the spheres in a volume of micro-meter dimension have important roles on properties. Recently, we have adopted a broad approach to grasping the morphology in large volume. A real space approach is Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) observations. A reciprocal space approach is Reverse Monte Carlo modeling of 3D positions of the spheres from ultra-small-angle X-ray scattering profiles observed in the synchrotron radiation facility SPring-8. Very recently, we confirmed consistency of the two approaches by evaluating scattering profile from the FIB-SEM data. We also performed large-scale coarse-grained molecular dynamics simulation to study the structure-property relationships.

2:00 PM  
The Digital Twin – A Comparative Study of Material Simulation on µCT-Scanned and Modelled Microstructures: Constantin Bauer1; Aaron Widera1; Tim Schmidt2; Florian Schimmer2; 1Math2Market GmbH; 2Institut für Verbundwerkstoffe GmbH
     Digital material engineering has recently become essential for many industrial applications. The simulation tools ability to create realistic representative microstructure models and to determine their physical material properties, helps in profitably quicken product development. The simulation software GeoDict is a straightforward solution for digital material analysis, engineering, and optimization.The materials’ microstructure is obtained either through import and segmentation of µCT-scans or by modelling the microstructure from direct input of material parameters. Both modelling approaches are provided by GeoDict and compared in this work. A continuous glass fiber reinforced fabric with thermoset matrix is scanned. The µCT-scans are imported into GeoDict and segmented to create a microstructure model. Mechanical and flow simulations, carried out on the microstructure model, determine its stiffness and permeability. As alternative, a digital twin of the material is modelled from input parameters and the simulation results are compared to those of the µCT-scan model.

2:20 PM  
Simulation of Material Properties Directly on CT Scans: Karl-Michael Nigge1; Johannes Fieres1; Philipp Schumann2; 1Volume Graphics GmbH; 2Concept Laser GmbH
    Classical FEM simulations may not always be well suited for micromechanical simulations of complex materials because they require the generation of geometry conforming meshes which must be fine enough to capture all relevant geometric details and coarse enough to keep the computational effort at a practical level on the other hand. Recently, mesh-less and immersed-boundary finite element methods have been used to overcome this meshing problem. In order to validate this simulation approach, a comparison between experimental and simulated results of tensile tests was conducted for material probes with complex internal structures, showing a good agreement. The approach was also validated successfully against a classical FEM simulation for a solid cube and a cubic lattice made. The simulation approach can be used to determine the effective mechanical properties of new materials with inherently complex internal structures.

2:40 PM  
Aggregate Presence and Impact of 3-dimensional Defect Populations in Additively Manufactured Stainless Steel: Jonathan Madison1; Laura Swiler1; Stephanie DeJong1; Thomas Ivanoff1; Brad Boyce1; Bradley Jared1; Jeffrey Rodelas1; Bradley Salzbrenner1; 1Sandia National Laboratories
    The salient relations between performance and processing defects of additively manufactured metals can be difficult to discern and often somewhat elusive to verify. To address this challenge micro-computed tomography was applied to an ensemble set of 100+ additively manufactured tensile samples of stainless steel. Tomographic datasets having resolutions of 10.2 microns per cubic voxel edge, or better, are utilized to identify and measure process-induced internal defect structure prior to mechanical testing. In this study, porosity and lack of fusion defects are the primary features of interest. Individual sample and aggregate build distributions for defect size, shape and spatial arrangements are reported in terms of their statistical presence. Correlations in observed defect presence will be shown and their relation to high-throughput mechanical testing results will also be highlighted.

3:00 PM Break