Microstructure design and mechanical properties of 3D printed graded lattice sandwich structures with tailored porosity

Abstract

A novel sandwich structure with graded lattice core was proposed, which achieves gradient design by means of tailored porosity. An analytical model was developed to determine the compression response of graded lattice cores of sandwich structures. To validate the analytical model, two types of graded lattice sandwich structures were fabricated via additive manufacturing and compression tests were performed. The analytical predictions were in good agreement with the experimental results. It was found that the effective Young's modulus of graded lattice sandwich structures is independent of porosity distribution pattern, but dependent on both porosity parameter and power law index. Meanwhile, as the porosity parameter increases, both yield stress and critical buckling stress decrease. The structure with SCI porosity distribution pattern exhibits superior load-bearing capabilities in graded lattice sandwich structures, indicating that desirable mechanical properties can be achieved through controlled structural porosity.