Computational Modeling of Fiber Orientation During 3D Concrete Printing (2023-03)¶

In 3D printing of fiber-reinforced concrete, fibers naturally align with the printing direction due to material shearing, enabling a certain degree of control over fiber orientation in component production. This contribution introduces an innovative integration of the Folgar-Tucker fiber orientation model into a fluid dynamics framework using the Particle Finite Element Method for simulating fiber orientation changes during 3D concrete printing. The fiber orientation state is characterized using a second-order orientation tensor, and an anisotropic Bingham model for the viscous fiber-concrete mixture describes fluid constitutive behavior. The model is validated by a comparison of the simulated orientation states a 3D-printed concrete layer, varying the extrusion nozzle diameters, with experimental data from the literature. Additionally, we conduct various parametric studies to investigate the flow dynamics, fiber realignment mechanisms, and the impact of process parameters on the fiber orientation within printed components.