Mechanical Properties of 3D-Printed Lattice Cylindrical Structure with Recyclable Elastomeric and Thermoplastic Polymers
摘要
Lattice structures are well known for their high strength-to-weight ratio and energy absorption. The mechanical properties of these lattices depend upon the geometrical configurations and these properties could be altered by change in design. The current work aims to study the effect of material and lattice cells on static and dynamic mechanical properties of lattice cylinders. For the combined study of the material and structural effect, both materials need to be far different. Due to this, the lattice cylinder was fabricated with thermoplastic polylactic acid (PLA) and an elastomeric thermoplastic polyester elastomer (TPEE). Before this study, these two dramatically different polymers using lattice cylinders had never been compared in a single study. Material extrusion (MEX) 3D-printing was used for manufacturing. Static compression tests, combined with digital image correlation (DIC), were utilized to analyze compression characteristics and deformation modes, and the results were validated through finite element method (FEM) analysis. From the results, due to the same lattice structure, the cylinders of both polymers exhibited similar densification strains as PLA and TPEE, 52.7% and 53.9%, respectively. Due to material effects, the energy absorption per unit volume (EA) of the two lattice cylinder structures is 200.90 and 3260 kJ/m3, respectively. The interlayer adhesion of materials is critical in determining the failure mode and compression behavior of a structure. PLA structural delamination causes the lattice holes to collapse, while TPEE fails due to the collapse of the connection holes. The lattice structure dominates the dynamic elastic recovery (DER) and Tan δ results.