Fracture characteristic analysis of cellular lattice structures under tensile load

The fracture characteristic analysis of three-dimensional lattice structures under quasi-static tensile load is explored by finite element method and the simulations are performed with three types of lattice structures: the rhombic dodecahedron and two types of BCC cellular lattice structures with different stacking directions. All the three types of lattice structures are made of ALSi10Mg alloy materials and manufactured using the selective laser melting technique. Also, tensile tests were carried out to obtain mechanical response and failure characteristic of different structures. This study presents the process of simulation by finite element method and the numerical results predicted with this method reveal novel fracture modes which are consistent with the experimental results respectively: The fracture of the DOD lattice structure is a progressive fracture process which is similar to the crack propagation. For BCC1 and BCC2 lattice structures, the fracture pattern is an entirely rupture along the fracture surface. The differences in the fracture modes of three lattice structures and the evolution processes of damage variables were investigated. In addition, the effects of diameter variation of the struts on the tensile behavior have been observed based on these studies.