Mixed-mode fracture behavior of 3D-printed PLA with zigzag filling

Abstract

Polylactic acid (PLA) is a widely used biomaterial in medical applications as a biodegradable and renewable aliphatic polyester type of material. This material is often subjected to different defects and damages from in-service and manufacturing conditions, and the increasing demand for PLA for different applications requires a thorough understanding of its fracture behavior. In this work, a numerical and experimental study of the mixed-mode fracture behaviors of three-dimensional (3D)-printed PLA samples with a zigzag pattern of different filling ratios was performed using a recently developed special loading fixture. The 3D-printed samples were produced with a 200°C nozzle at 60°C bed temperature and 50 mm/s printing speed. Mixed-mode fracture tests from pure tensile to pure shear loading were performed by varying the loading angle, α, from 0 to 90°. Finite-element analyses were conducted by using the Abaqus software program, and geometrical factors were obtained at different loading angles. As a result, the fracture toughness values of pure tensile loading, pure shear loading and mixed modes were determined.

Investigation of mechanical and fracture behavior of pure and carbon fiber reinforced ABS samples processed by fused filament fabrication process

“…This material property is used in the design to characterize the resistance to fracture. The stress intensity factor K C at the tip of a crack in a specimen is given by Torun et al (2020), Oskui et al (2016); and Yayla (2019):…”

“…Rahmani et al (2019) investigated the fracture toughness, delamination strength and fractography of the fracture surface of CF reinforced polymer-based composites between À80 and 122°C experimentally and numerically using Arcan fixture. Torun et al (2020) conducted mixed-mode fracture tests on PLA samples processed with a zigzag pattern at different filling rates on a 3D printer. They found that, by increasing the loading angle, the Mode I geometric function value decreased and the Mode II stress intensity factor value increased.…”

Exploring mixed-mode fracture behavior and mechanical properties of selective laser sintered polyamide 12 components

“…Understanding the fracture behavior of materials under varying conditions, such as different fabrication parameters and loading conditions, is crucial for their use as structural elements (Hossein Abadi et al , 2020). Additive manufacturing has facilitated the production of samples with specific configurations and crack lengths for investigating the fracture behavior (Hossein Abadi et al , 2020; Torun et al , 2020; Linul et al , 2020; Brugo et al , 2016; Cano et al , 2018). Studies have commonly examined the mixed-mode fracture behavior of fused deposition modeling (FDM) printed parts.…”

“…Similar methods were used to study the fracture behavior of samples fabricated using the FDM technique. Recently, Torun et al (2020) fabricated 3D-printed polylactic acid (PLA) samples with a zigzag layout to investigate the effects of filling ratios on mixed-mode fracture behavior. The authors observed that for all filling ratios, the shear mode stress intensity factor (SIF) increased with the loading angle from 0° to 90°, while the opening mode critical SIF decreased.…”

A Study on the Effects of the Interior Architecture on the Fracture Toughness of 3D Printed PLA Samples

“…They determined that the chitosan reinforcement and the filling density were important parameters in the strength of composite specimens, but the annealing temperature did not affect it much. Torun et al (2020) produced zigzag printed PLA samples to examine the effects of filling ratios on the mixed-mode fracture behavior of 3D printer components. For all filling ratios, they reported that when the loading angle was increased from 0° to 90°, the shear mode stress intensity factor increased and the tension (opening) mode critical stress intensity factor decreased.…”