Modelling of 3D concrete printing based on computational fluid dynamics

Abstract

This paper presents a computational fluid dynamic model of 3D Concrete Printing. The numerical simulation is used to predict the cross-sectional shape of 3D printed segments through “virtual printing” simulations. An experimental parametric study of the layer geometry is also conducted for a wide range of processing printing speeds and nozzle heights. The constitutive behavior of the cement-based mortar used in experiments is characterized by rotational and oscillatory rheological tests, and it is modelled with a Bingham constitutive law. Moreover, two formulations of the constitutive law are used in the simulations: the generalized Newtonian fluid model, and the elasto-visco-plastic fluid. Overall, the numerical results agree well with the experiments, validating the proposed computational fluid dynamics modelling approach. Finally, an example of multi-layer print simulations as well as research prospects are presented.