RVE: Representative Volume Element
Explanation:A Voronoi cell generator is able to create a polycrystalline volume model. In order to guarantee a representative volume, the model is periodic in each geometric direction. The cubic mesh is generated by means of raster space discretization. All elements are arranged by the nearest neighbor sweep circle method, which aligns all elements within an incrementally growing circle to a specific seed point within the RVE. Another method is to calculate the minimum distance between an element and all seeds, which is more accurate but inefficient due to the explicit calculation. An improved method for tessellating a space is the Delaunay triangulation. This method is an exact Voronoi diagram in vector representation. This method is applied for RVE with tetragonal mesh.
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RVE and microstructural model for high Mn steels.
SFB-Link:The developed microstructural model is able to describe the material morphology of high manganese steels by means of Voronoi tessellation. The grain size and chemical distribution within the polycrystalline aggregate can be modeled according to microscopy investigations and XRD measurements. Beside the temperature, the locally varied chemical composition is the main factor controlling the stacking fault energy (→SFE). The variables in the RVE are used for calculation of the SFE is a direct link to the material model, which describes the hardening behavior. A microstructural model for flow curve and failure modeling based on the RVE approach is developed for high Mn steels. The polycrystalline structure is generated by discrete Voronoi tessellation. The RVE tool can also be used for generating the microstructure for other advanced high strength steels (→AHSS) and can also be used for generating banded microstructure.
References:R. Twardowski, PhD Thesis, Mikrostrukturelle Beschreibung von Verformung und Schädigung hochmanganhaltiger Stähle mit TRIP- und TWIP-Effekt.
R. Twardowski, D. Steinmetz, and U. Prahl. Flow curve and failure modelling for high-Mn steels on a microstructural scale. SRI 2012