Numerical Modeling of an Extrusion-Based 3D Concrete Printing-Process Considering a Spatially-Varying Pseudo-Density Approach (2020-07)¶

During the past few years, additive manufacturing techniques for concrete have gained extensive attention. In particular, the extrusion-based 3D concrete printing exhibited a rapid development. However, further progress is hampered by a time-consuming trial-and-error exploration, i.e., mainly experimental studies have been performed so far. A more fundamental understanding of the relations between the printing process, the process parameters and the properties of the printed product could be achieved by means of numerical simulations. They enable to study a wide range of parameters such that dependencies of properties of the printed product on different influencing factors can be identified. Taking into account the uncertain nature of the process and material parameters of the extrusion-based 3D concrete printing, the process can be reliably controlled and finally optimized. The present study introduces a novel modeling approach, applying the Finite Element (FE) method while considering a pseudo-density approach. This density is used to define the material properties of each FE, similarly to the soft-killing approaches in topology optimization. Along with the progressing printing process, a previously generated FE mesh is activated layer by layer. Additionally, all material parameters vary temporarily due to the time dependency of the curing process. The numerical simulation allows to investigate the deformation behavior of the printed wall for different printing velocities.