Effect of surface quality on the fracture behavior of 3D printed lattice structures

The fracture behavior of rhombic dodecahedron (DOD) and body-centered cubic (BCC) 3D printed lattice structure considering surface roughness was investigated. Tensile tests on flat specimens with different surface roughness were performed, which indicates surface quality has an important influence on the fracture elongation. Smoothed round and round notched tensile specimens were also tested to calibrate damage constitutive model parameters. Based on the statistical data of the diameter variations of the struts and a progressive damage material model, FEM models were built to simulate the fracture behaviors of lattice structures. The simulation results are consistent with the experimental ones and damage evolution characteristics of the fractured struts are discussed. It’s proved that surface roughness is a key factor to affect the strength of the lattice structure and fracture behavior.