Finite element simulation of the compressive response of additively manufactured lattice structures with large diameters

This study focuses on the use of beam element based finite element models to predict the compressive response of 316L stainless steel lattice structure with a body center cubic (BCC) topology. A methodology is developed to compensate for the inadequate stiffness in the joint regions of the beam element model. Numerical results from the modified beam element model agreed well with the corresponding solid model results for all the three diameters under compressive response, including where the strut aspect ratio (diameter/length) was greater than 0.2. A series of lattice specimens was built, and compressive experiments were conducted. As a result, simulation results of the stress-strain curve and deformation modes using both the three-dimensional continuum and the beam element model with identified material parameters for all three different diameters had a good consistency with experimental data under quasi-static compressive loads. The developed beam element-based FEM model can contribute to more effective computation of the lattice embedded structure performance than the solid element based model due to its lower computational cost.