Abstract
Additive manufacturing is becoming increasingly popular in academia and industry. Accordingly, there has been a growing interest in characterizing 3D printed samples to determine their structural integrity behaviour. We employ the Essential Work of Fracture (EWF) to investigate the mechanical response of polymer sheets obtained through additive manufacturing. Our goal is twofold; first, we aim at gaining insight into the role of fibre reinforcement on the fracture resistance of additively manufactured polymer sheets. Deeply double-edge notched tensile (DDEN-T) tests are conducted on four different polymers: Onyx, a crystalline, nylon-reinforced polymer, and three standard polymers used in additive manufacturing – PLA, PP and ABS. Results show that fibre-reinforcement translates into a notable increase in fracture resistance, with the fracture energy of Onyx being an order of magnitude higher than that reported for non-reinforced polymers. On the other hand, we propose the use of a miniature test specimen, the deeply double-edge notched small punch specimens (DDEN-SP), to characterize the mechanical response using a limited amount of material. The results obtained exhibit good alignment with the DDEN-T data, suggesting the suitability of the DDEN-SP test for measuring fracture properties of additively manufactured polymers in a cost-effective manner.
Highlights
Afterwards, we assess the capabilities of the doubleedge notched small punch (DDEN-SP) testing procedure in evaluating the mechanical and fracture properties of polymeric materials obtained by additive manufacturing (Section 3.2)
DL b 0.1 indicates brittle fracture, 0.1 b DL b 0.15 is the regime of ductile instability, the range 0.15 b DL b 1 is known as post-yielding, blunting is characteristic of 1 b DL b 1.5, and necking is the main dominant failure mechanism when DL N 1.5
We use the Essential Work of Fracture (EWF) method to characterize the mechanical and fracture properties of polymeric materials that have been obtained by fused deposition modelling (FDM)-based additive manufacturing
Summary
One of the main advantages of additive manufacturing is the reduced time elapsed from the conception of the component to its final manufacture, as it does not require the design and production of special tools through other production processes. Due to its low upfront cost, fused deposition modelling (FDM) is one of the techniques with greater future prospects. This technology is based on heating a polymer above its glass transition temperature, and depositing it layer by layer with a nozzle. The main drawbacks of FDM are the notable surface roughness levels and, common to other additive manufacturing techniques, the poorer mechanical performance of the samples (relative to traditional manufacturing methods). Most works aim at assessing the role of printing process parameters on the mechanical properties (see [1,2,3,4,5,6,7,8,9,10], and references therein) but there are studies related to fracture and fatigue properties [11,12,13], and high temperature performance [14,15]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
