Standard-Driven Parametric Modelling Framework for Automated Generation of Railway Ballast Geometry Database

Accurate representation of ballast particle geometries is a critical prerequisite for computer-aided design and discrete-element simulation of railway track beds. However, a major bottleneck lies in the absence of an efficient and systematic process to translate industry standards into compliant aggregate-level geometry databases. To address this, a standard-driven parametric modelling framework is presented for the automated generation of such databases. In the framework, particles are modelled as parametrically controlled polyhedra through circumscribed ellipsoids. First, a hybrid algorithm is employed, integrating octant partitioning, a beta distribution, and Voronoi tessellation to optimise vertex distribution; then orthographic projection and the rotating caliper method are utilised to validate that each polyhedron’s size and shape comply with industrial standards. Validation results demonstrate the framework’s high efficiency and precision, with a 100 kg superior-grade ballast geometry database generated in 55.23 s, achieving mean absolute errors of 0.03% for gradation and 0.23% for shape indices. The proposed framework not only provides a foundational tool for digital design and simulation in railway engineering but also presents a transferable methodology for the geometric modelling of general particle systems in other fields.