Investigating Fracture Behaviour of Single-Cell Lattice Materials via XFEM: Voxel-based Approach

This study uses the extended finite element method (XFEM) and voxel-based approach to numerically investigate additively manufactured single-cell lattice materials’ fracture behavior (e.g., crack growth and fracture resistance) under tensile loading. Body-centered cubic (BCC) single-cell lattices were manufactured from Polylactic acid (PLA) with a strut diameter of 1.5 mm using the fused filament fabrication (FFF) technique. The micro-CT imaging was utilized to provide detailed information on defects (e.g., voids, gaps, and cracks) inside the lattices, improving the exactness of the models used in the numerical investigations. The 2D micro-CT images were then converted to 3D voxel models through MATLAB programming. The generated models were numerically analyzed using the XFEM technique, in which the crack initiation and propagation were modeled via maximum principal stress (MaxPS) and power-law fracture criteria, respectively. A comparison was made between the results of XFEM analyses obtained from the single-cell solid and voxel BCC lattice models.