Application of cellular automata and Lattice Boltzmann methods for modelling of additive layer manufacturing

• Published in: International journal of numerical methods for heat & fluid flow 2018-01, Vol.28 (1), p.31-46
• Main Authors: Svyetlichnyy, Dmytro, Krzyzanowski, Michal, Straka, Robert, Lach, Lukasz, Rainforth, W. Mark
• Format: Article
• Language: English
• Subjects: Additives; Bioengineering; Bones; Cellular automata; Cellular manufacture; Composite materials; Computational fluid dynamics; Computer science; Computer simulation; Energy absorption; Fluid flow; Heat; Heat exchange; Heat transfer; Heating; Heavy metals; Hydrodynamics; Implants; Interfaces; Laser beam heating; Laser sintering; Lasers; Liquid flow; Liquid phases; Liquid-solid interfaces; Manufacturing; Materials science; Mathematical models; Melting; Methods; Modelling; Numerical analysis; Orthopaedic implants; Physical phenomena; Rapid prototyping; Scale models; Sequencing; Simulation; Solidification; Solids; Tissue engineering
• ISSN: 0961-5539; 1758-6585
• DOI: 10.1108/HFF-10-2016-0418

Purpose The holistic numerical model based on cellular automata (CA) and lattice Boltzmann method (LBM) are being developed as part of an integrated modelling approach applied to study the interaction of different physical mechanisms in laser-assisted additive layer manufacturing (ALM) of orthopaedic implants. Several physical events occurring in sequence or simultaneously are considered in the holistic model. They include a powder bed deposition, laser energy absorption and heating of the powder bed by the moving laser beam, leading to powder melting or sintering, fluid flow in the melted pool and flow through partly or not melted material, and solidification. The purpose of this study is to develop a structure of the holistic numerical model based on CA and LBM applicable for studying the interaction of the different physical mechanisms in ALM of orthopaedic implants. The model supposed to be compatible with the earlier developed CA-based model for the generation of the powder bed. Design/methodology/approach The mentioned physical events are accompanied by heat transfer in solid and liquid phases including interface heat transfer at the boundaries. The sintering/melting model is being developed using LBM as an independent numerical method for hydrodynamic simulations originated from lattice gas cellular automata. It is going to be coupled with the CA-based model of powder bed generation. Findings The entire laser-assisted ALM process has been analysed and divided on several stages considering the relevant physical phenomena. The entire holistic model consisting of four interrelated submodels has currently been developed to a different extent. The submodels include the CA-based model of powder bed generation, the LBM-CA-based model of heat exchange and transfer, the thermal solid-liquid interface model and the mechanical solid-liquid interface model for continuous liquid flow. Practical implications The results obtained can be used to explain the interaction of the different physical mechanisms in ALM, which is an intensively developing field of advanced manufacturing of metal, non-metal and composite structural parts, for instance, in bio-engineering. The proposed holistic model is considered to be a part of the integrated modelling approach being developed as a numerical tool for investigation of the co-operative relationships between multiphysical phenomena occurring in sequence or simultaneously during heating of the powder bed by the moving high ene