Cavity prediction in sand mould production applying the DISAMATIC process

Abstract

The sand shot in the DISAMATIC process is simulated by the discrete element method (DEM) taking into account the influence and coupling of the airflow with computational fluid dynamics (CFD). The DEM model is calibrated by a ring shear test, a sand pile experiment and a slump test. Subsequently, the DEM model is used to model the propagation of the green sand inside the mold chamber and the results are compared to experimental video footage. The chamber contains two cavities designed to quantify the deposited mass of green sand. The deposition of green sand in these two cavities is investigated with three cases of different air vent settings which control the ventilation of the chamber. These settings resulted in different air-and particle-velocities as well as different accumulated masses in the cavities, which were successfully simulated by the model.

Experimental validation of a numerical model for the strand shape in material extrusion additive manufacturing

“…Numerical modelling has been widely used to acquire knowledge about processes [29], for example in ceramics tape casting [30,31], or in the production of sand molds [32,33], to cite a few. In the field of material extrusion AM, numerical models have been developed to simulate the temperature distribution and the cooling rate of the extruded material [34,35,36,18,37].…”

Numerical simulations of the mesostructure formation in material extrusion additive manufacturing

“…In complement to experimental studies, numerical simulations can deliver a vast amount of information about the process and have proven to be a predictive tool in the analysis of different manufacturing methods [36][37][38][39]. In the context of material extrusion AM, the extrusion flow has been investigated using two-dimensional [40][41][42], and three-dimensional Computational Fluid Dynamics (CFD) simulations [43][44][45][46][47][48].…”