Parameter Study of GTN Model in a SLM Manufactured Lattice Structure under Compression by Using FEM

This study investigates the effect of material parameters of the Gurson-Tvergaard-Needleman (GTN) model on the failure prediction of cellular structures. The effect of elastic modulus, calibration parameter of GTN model, isotropic hardening, fracture strain, and strut diameter on the load-displacement curve of a lattice structure fabricated by Selective Laser Melting (SLM) has been studied by using the finite element method. The power law of Hollomon has been used to model the isotropic hardening behavior. The considered lattice structure is made of AlSi10Mg alloy, which is used in different industries. A 20cm×20cm×20cm structure with 4 Body Centered Cubic (BCC) unit cells in x, y, and z directions have been considered. The results show that 250000 elements for one-quarter of the lattice structure are quite enough to obtain acceptable results. The effect of prescribed parameters on the load-displacement curve of the lattice structure has been studied. Based on the obtained results, diameter and hardening behavior are the most influential parameters and the significant effect on load-displacement curve has been observed.

Keywords:

Parameter Study , GTN model , Isotropic hardening , SLM