NUMERICAL SIMULATIONS FOR ADDRESSING FLAWS IN THE FREIGHT WAGON DESIGN, ACHIEVING GOAL OF INCREASED EXPLOITATION FUNCTIONALITY

Abstract

In this paper, the problem of deposition of granular material during unloading of freight wagon is addressed. The problem occurs as a result of design flaws, in particular insufficient angles of slopes. On these tilted surfaces certain amount of granular materials remains after the wagon is emptied which increases unloading time and operation costs. In order to analyze unloading process, numerical simulations which utilize linking of Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH) are used. Granular material is modelled with meshless SPH method, while wagon geometry is modelled with FEM. This allows engineers insight into significance of material properties and contact parameters which governs interaction between wagon and granular material. Numerical simulations result show that slight decrease of friction coefficient removes deposition. To achieve this on existing wagons, coating of contact surfaces is proposed. This is the most practical solution considering number of wagons that are already constructed. The same methodology can be implemented while designing new wagons. Smooth interaction of granular materials with wagon surfaces can be ensured during design phase, thus removing a need for subsequent surface treatment.