Effect of process parameters on mechanical properties of 3D printed PLA lattice structures

Abstract

In this paper, the mechanical properties of 3D printed PLA lattice structures were studied using digital image correlation (DIC), and the effect of process parameters on the mechanical properties of the samples was discussed. First, tensile samples and lattice structures of the PLA were prepared by Fused Deposition Modeling (FDM). Then the tensile experiments were carried out on the tensile samples, and the tensile strength and elastic modulus were obtained. Moreover, the compressive experiments were carried out on the 3D printed PLA lattice structures, and the yield strength, plastic platform stress and densification strain were obtained. The full field displacements and strains were obtained using DIC. Finally, scanning electron microscope (SEM) was used to study the cross-section of the sample, and the mechanism of the influence of process parameters on the sample was analyzed. The experimental results show that as the printing temperature increases, the tensile strength and elastic modulus tend to rise first and then decrease. When the printing temperature is 230 °C, the maximum tensile strength is 50.16 MPa, and the tensile elastic modulus is 4340.38 MPa. While the yield strength, plastic platform stress and densification strain of lattice structures show a downward trend. As the printing speed increases, the tensile strength and elastic modulus show an upward trend, and when the printing speed is 60 mm/min, the tensile strength and elastic modulus are 51.47 MPa and 5102.12 MPa respectively. Moreover, the yield strength, plastic platform stress of lattice structures show a downward trend, densification strain show an upward trend.