Modelling and FE simulation of 3D printed Co-Cr Lattice Structures for biomedical applications

The lattice structures are a particular type of structures made by the repetition of a unit cell and show great design opportunities. In addition, their structure is really close to some physiological tissues, which can allow their use to develop prostheses needed to the rehabilitation or replacement of a body part. However, their use is still limited, mainly due to the lack of methods to fully implement them during the production and to virtually predict all their mechanical properties. This problem is mostly caused by the computational effort and number of design parameters that the implementation of these materials in a Finite Element Modelling (FEM) analysis requires. Moreover, many common CAD software have a lack of materials libraries and geometry flexibility. In this work, samples with different lattice structures were manufactured by Laser Powder Bed Fusion technique using Co-Cr-Mo alloy. Compression tests were carried out to characterize their mechanical behavior. Subsequently, modelling and FE simulations were carried out to predict their mechanical response. In fact, a Finite Element Analysis allows to have a preview of final designed structure and to reduce the experimental tests otherwise needed to reach the final design, saving time and resources. Numerical simulations of the compression test were performed by FEM code Abaqus, in order to explore the possibilities and limitations of this approach for the study of lattice structures. Results of numerical simulations were compared with experimental data. Finally, NTopology software was also used to study the stiffness of the lattice structures according to the geometry of the investigated unit cells.