A coupled thermo-mechanical model for the simulation of discrete particle systems in advanced manufacturing.

Abstract

Modern industry, such as in aerospace, automotive, biomedical and military fields, has adopted advanced manufacturing (such as particle sintering-like processes and other 3D printing) as a rapid and efficient alternative for manufacturing industrial parts. Also, state-of-the-art techniques in the civil engineering industry include 3D concrete printing and cement-based additive manufacturing processes. All these techniques invariably include thermally-active particles, such as sintering powders and functionalized cementitious materials. The purpose of this work is to present a thermo-mechanical model for the simulation of problems involving thermo-mechanically-active particles forming discrete particles systems in advanced manufacturing. Our approach is based on the Discrete Element Method (DEM), combined with lumped heat transfer equations to describe the various thermal phenomena that may take place for such systems. Particles' motion and their thermal states over time are computed under the influence of body (e.g., gravitational) forces, contact and friction forces (and the related moments w.r.t. the particles' centers), adhesive forces as well as applied heat from external devices, heat transfer through conduction (upon contact with other particles and objects), convective cooling and radiative effects. Phase transformation, which may be critical in certain applications, is also considered. A numerical scheme is presented for solution of the model's equations. We then develop direct, large-scale numerical simulations to illustrate the validity of the proposed scheme and its practical use to the simulation of modern advanced manufacturing processes.Keywords: Particles, thermo-mechanical effects, multiphysical particle systems, advanced manufacturing and 3D printing, discrete element method (DEM) v QUINTANA RUIZ, Osvaldo Dario. Um modelo acoplado termo-mecânico para a simulação de sistemas discretos de partículas em manufatura avançada. 2021. Num de Pág. 151 f. Tese (Doutor em Ciências) -