Simulating material flow and extrusion dynamics in 3D concrete printing

We present an advanced 3D virtual printing framework for simulating material flow and extrusion dynamics in 3D concrete printing (3DCP), specifically addressing critical layer transition challenges. Central to the framework is a gradually-rising printing-start model, which dynamically adjusts deposition to eliminate sharp discontinuities between layers. Computationally, the framework couples δ-smoothed particle hydrodynamics (δ-SPH) with a regularized Bingham model to accurately capture deformation and pressure fields of extruded concrete. An alternating particle generation algorithm further enhances efficiency by enabling on-demand creation of fluid and wall particles, with parallelization supporting scalable simulations. Benchmark validations confirm the framework’s accuracy in modeling Bingham fluid behavior and its computational robustness. Results indicate that initial nozzle pressure strongly influences extrudability, with higher pressures producing greater layer deformation. The gradually rising deposition model aligns closely with theoretical predictions, expanding the transition zone and improving interlayer bonding. Beyond predictive failure analysis, this framework facilitates optimization of 3DCP parameters, paving the way for more reliable and scalable additive construction processes.