ABSTRACT
Additive manufacturing techniques, among which 3D Concrete Printing (3DCP) and polymer extrusion are revolutionizing the production process, offering unprecedented design freedom and efficiency. To control these technologies and fully exploit their potential it is necessary to develop efficient and reliable numerical tools.
In this talk, a general framework to simulate the extrusion and layer deposition processes of non-Newtonian fluids with the Particle Finite Element Method (PFEM) will be presented. The PFEM is a mesh-based Lagrangian approach, which results to be particularly appealing for the simulation of complex fluids and free-surface flows. A PFEM 3D printing framework has been implemented in an in-house code, addressing several challenges such as the imposition of time-dependent moving boundary conditions and inter-layer contact. Moreover, an adaptive de-refinement technique is used to decrease the computational cost while preserving accuracy.
Concerning the material behaviour two rheological models are considered: a viscoplastic Bingham law and a viscoelastic Oldroyd-B law. The former model has been successfully employed for the simulation of the extrusion of cementitious materials, and it is validated by comparing the simulation results with proper experimental data. The latter is instead more representative of polymers, and it is tested on standard viscoelastic free-surface benchmarks, such as the impacting drop and the jet buckling problems.
SPEAKER CV
Giacomo Rizzieri is a civil (structural) engineer who graduated from Politecnico di Milano. Currently, he is enrolled in the third year of PhD in Structural, Seismic and Geotechnical Engineering at Politecnico di Milano. His PhD research involves the development of new computational tools for the simulation of non-Newtonian fluids, with a specific focus on modelling 3D printing of cementitious materials. From November 2023 to February 2024 Giacomo has been spending a research period at CIMNE working on the implementation of FEM techniques for the simulation of free-surface fluid flows in the context of the Particle Finite Element Method.
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