Simulation of the mechanical behavior of lattice structure components with a multiscale approach.

With the development of Additive Manufacturing, it has become possible to create components with complex geometries, such as lattice or reticular structures. Thanks to their high specific energy absorption combined with low mass, these structures have proven to be very interesting in terms of mechanical properties. The aim of this thesis is to create a numerical model that allows estimating the mechanical behavior of 3D printed components with lattice structures using a multiscale approach. Micro Computer Technology analyses performed on AlSi10Mg lattice specimens revealed the presence of internal porosity within the lattice structure. To account for these internal defects, a multiscale approach was adopted, allowing for faster and more precise simulations at the microscopic level with three-dimensional elements incorporating defects, using Abaqus CAE for Finite Element Analysis. Equivalent mechanical properties were obtained and extended to the macroscopic level of the component. LS-Dyna software was then used to perform simulations directly on the lattice specimen, associating the mechanical characteristics obtained at the microscale with each 1D element of the mesh. The Stress-Strain curves obtained at the microscale, by randomly introducing defects into the structure, resulted in a variability of mechanical response in the lattice specimen. Subsequently, the lattice specimen underwent a quasi-static compression test, yielding a force-displacement response. The family of numerical curves generated from the multiscale Finite Element Analysis allowed for the creation of a band that contained the experimental curve, thus accurately simulating the mechanical behavior of the lattice structure and validating the numerical model.