Fracture behavior of anisotropic 3D-printed parts: experiments and numerical simulations

Abstract

The extrusion-based additive manufacturing (AM) is currently the most common there-dimensional (3D) printing for the fabrication of polymer components. In this study, the fracture behavior of 3D-printed polymer parts is investigated. To this aim, polylactic acid material (PLA) was used to print intact and defected specimens based on the fused deposition modeling (FDM) process. The specimens were printed with three different raster directions to determine their effect on the fracture behavior of the parts. Moreover, wood-reinforced PLA material was used to print another group of test coupons. All specimens were subjected to a series of tensile tests and their fracture behaviors are investigated. Based on the comparison of the results, the influence of reinforcement is determined. In addition, parallel to the experiments, a series of finite element analyses were conducted utilizing the anisotropic phase-field fracture model. For an efficient calculation, we treated the whole specimen as a homogenized solid where the anisotropic property of the layered material is considered in the formulation. By calibrating the model based on the experimental measurement, one can predict the anisotropic fracture behavior of the 3D-printed part with high precision. Since applications of 3D-printed composites have been significantly increased, the results of this study can be used for optimization, further numerical analysis, and next development.

Keywords

• Defect
• Crack propagation
• Additive manufacturing
• Anisotropic phase-field fracture