| Additive manufacturing technology,also called 3D printing,has been developing rapidly in recent years,which makes materials and structures with extraordinary micro geometric configuration realized industrially.Cellular lattice materials that are widely used in aerospace,rail traffic,biomedicine and other fields could be manufactured easily from now on.Hence,based on the requirements for the design of mechanical properties and engineering application,the mechanical behavior of Al Si10 Mg alloy lattice materials with rhombic dodecahedron and BCC unit cells fabricated by selective laser melting was investigated in this paper by using theoretical model,mechanical test and FE simulation.The main work includes:1.The relative density and porosity of the lattice materials were introduced,and the relation between the radius-length ratio of beam and relative density was proved.The famous Gibson-Ashby model is introduced and deduced,compared the theoretical result of two kind of unit cells with experiments and simulations,it is concluded that the model proposed from Gibson and Ashby could be an appropriate prediction for elastic modulus irrespective of anisotropy.2.The Al Si10 Mg rhombic dodecahedron and BCC cellular lattice materials were fabricated by selective laser melting process.Variety mechanical experiments were carried out to obtain stress-strain behavior and failure mechanism.Meantime,the test methods of metal lattice materials were developed.3.Finite element models based on combined elements were developed to investigate the local stress and strain distributions and compare them with experimental results,the plastic behavior and collapse stress were discussed as well.A script was developed through python to generate model with variable cross sections using beam element.The result show that,to obtain a good accuracy,it is necessary to model the cross section variations along the strut's length.The effect of relative density on compressive property was also investigated. |
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