Neper: polycrystal generation and meshing

Neper is a software package for polycrystal generation and meshing. It can deal with 2D and 3D polycrystals with very large numbers of grains. Its main features are:

  • Generation of polycrystals from (experimental) morphological properties

    • Grain size distribution, grain shape distribution, etc.
    • Grain-by-grain data as obtained for example in synchrotron X-ray diffraction (3DXRD, DCT, HEDM, ...) and such as grain centroids/volumes or a full polycrystal image.

    Standard approaches (regular tessellations and Voronoi or Laguerre tessellations) are also available.

  • Generation of multiscale microstructures

    Each cell of a primary tessellation is partitioned into a new tessellation, and the process can be repeated an arbitrary number of times. This can be used to mode complex microstructures such as bainitic steel, lamellar Ti-6Al-4V, etc.

  • Generation of periodic or semi-periodic microstructures

    The tessellations (and their meshes) can be prescribed periodic or semi-periodic conditions to cancel the effect of free surfaces or reduce the size of the RVE.

  • Meshing into good-quality elements

    Meshing involves specific methods called regularization, multimeshing and remeshing. The mesh size can be uniform or defined on a per-grain basis.

  • Meshing with cohesive elements at interfaces

  • Visualization and analysis of the tessellations and meshes

    The scene can be set in great detail and images are generated with publication-quality rendering (see the image on the right). Several metrics are available on the morphological and topological properties.

Neper is built around three modules: generation, meshing and visualization. All the input data are prescribed non-interactively, using command lines and / or ASCII files. Neper can be compiled and run on any Unix-like system.