Compression and Energy Absorption Performances of 3D Printed Polylactic Acid Lattice Core Sandwich Structures

To avoid the problem of weak connections between panel sheets and core layers of lattice structures obtained by the traditional fabricating method, lattice structures of polylactic acid were integrally manufactured by fused deposition modeling of 3D printing technology in the present study. An orthogonal test was designed to evaluate the influence of the core distance, core diameter, and core length of lattice structures on their compression and energy absorption properties. Theoretical analysis and the finite element method were conducted to predict compression properties of lattice structures. The optimum specification of the lattice structure in this article with regard to specific strength was as follows: core distance 18 mm, core diameter 12 mm, and core length 20 mm. The lattice structure has good specific strength and specific energy absorption and can be comparable with an aluminum lattice. The failure mode of the lattice structure was determined to be crushing of the core, and no damage to the joint between the core and face sheet was observed.