Numerical Investigation of the Cycling Loading Behavior of 3D-Printed Poly-Lactic Acid (PLA) Cylindrical Lightweight Samples during Compression Testing

Abstract

The additive technologies widely used in recent years provide enormous flexibility in the production of cellular structures. Material extrusion (MEX) technology has become very popular due to the increasing availability of relatively inexpensive desktop 3D printers and the capability of fabricating parts with complex geometries. Poly-lactic acid (PLA) is a biodegradable and commonly applied thermoplastic material in additive manufacturing (AM). In this study, using a simulation method based on the user subroutine titled “user subroutine to redefine field variables at a material point” (USDFLD) in the finite element method (FEM) ABAQUS software, the elastic stiffness (ES) of a cylindrical lightweight cellular PLA sample with a 2.4 mm infill line distance (ILD), which was designed as a layered structure similar to the laboratory mode with a MEX method and was subjected to cyclic compressive loading, was investigated by considering the variation of the Young’s modulus depending on the variation of the equivalent plastic strain (PEEQ). It was observed that the PLA sample’s elastic stiffness increases during cyclic loading. This increase is high in the initial cycles and less in the subsequent cycles. It was also observed that the simulation results are in good agreement with the experimental results.