Experimental and FEM investigation of BCC lattice structure under compression test by using continuum damage mechanics with micro-defect closure effect

The failure of the cellular structures and the prediction of their limit load and type of failure are essential in their design and applications. The isotropic Continuum Damage Mechanics (CDM) model of Lemaitre with micro-defect closure effect was considered to simulate the mechanical response of the BCC lattice structure under a compression test. Defects caused during the manufacturing process is considered an initial damage. The simulation results of the compression tests on the 316L Stainless Steel (SS) lattice structures, which were manufactured by the Selective Laser Melting method (SLM), and the experimental results have been compared. The same study was conducted on the AlSi10Mg manufactured lattice structures. FE simulation showed that the CDM model can predict the elastic modulus and yield strength of the lattice structure with good accuracy. The stress–strain curve of the lattice structure, obtained from the FE simulation, agrees well with the experimental results before the condensation. According to the conducted experiments, the failure mechanism for the considered cases is bending dominated with high plastic deformation at the connection area of nodes and struts. The present model predicts the state of damage of the structure with good accuracy and it is in agreement with the experimental results.