A parametric modelling strategy for the numerical simulation of 3D concrete printing with complex geometries

Three-dimensional concrete printing (3DCP) is a fast-evolving manufacturing technique in the construction industry with numerous advantages over traditional construction methods. Nevertheless, many unknowns about 3DCP in the manufacturing stage still remain, such as the maximum number of printed layers before failure or the maximum speed at which a certain design can be properly printed. In this paper, a numerical model for the simulation of the structural behaviour of 3D printed fresh concrete is proposed and discussed. In order to obtain complete control over the additive process, material properties and layer interactions, the finite element mesh needs to be created from the ground up in a layer-wise manner. Therefore, a parametric tool was developed, which allows for the creation of finite element models without requiring extensive manual modelling. The main advantage of the developed tool is the possibility to automate the pre-processing step for the numerical analysis and simulate the structural behaviour of a randomly shaped object during printing. Additionally, it allows for finding the appropriate material properties for a certain print object at a desired print speed and vice versa. As such, the printing process can first be virtually simulated and improved upon without physical experimentation and the corresponding material waste. Ultimately, the developed tool can assist in an entire 3DCP workflow with regard to efficiency and material usage. Models created with the presented tool were evaluated and validated based on experimental and numerical results from literature. Finally, the case study of a geometrically complex print object is presented, demonstrating the tool's potential.