Evaluation of Tensile Properties and Damage of Continuous Fibre Reinforced 3D-Printed Parts (original) (raw)
Related papers
Materials
This paper introduces novel research into specific mechanical properties of composites produced by 3D printing using Continuous-Fiber Fabrication (CFF). Nylon (Onyx) was used as the composite base material, while carbon constituted the reinforcement element. The carbon fiber embedment was varied in selected components taking values of 0°, 45°, 90°, and 135° for parts undergoing tensile testing, while one specific part type was produced combining all angles. Carbon-fiber-free components with 100% and 37% fillings were also produced for comparison purposes. Parts undergoing the Charpy impact test had the fibers deposited at angles of 0° and 90°, while one part type was also produced combining the four angles mentioned before. Carbon-fiber-free parts with 100% and 37% fillings were also produced for comparison purposes as with the first part. The Markforged MARK TWO 3D printer was used for printing the parts. These were subsequently scanned in the METROTOM 1500 computed tomography and ...
3D printed fiber reinforced polymer composites - Structural analysis
Composites Part B: Engineering, 2019
In this research, mechanical and structural properties of Continuous Fiber Reinforced Additively Manufactured (CFRAM) components are studied. Structural analysis is performed to understand the failure behaviour of CFRAM components. Based on the SEM analysis of the tested parts, correlations between results of mechanical test and microstructure of the parts have been investaged. CFRAM components are lightweight yet strong materials with a wide range of potential applications in auto industry, aerospace, sport goods, and medical tools. CFRAM components benefit from both cutting-edge 3D printing technology and fiber reinforcement to improve mechanical properties. Produced parts have lightweight compared with metals, strong mechanical properties, and short manufacturing time. In addition, thermoplastic polymer used for CFRAM components makes product recyclable. In this study, samples were printed using Markforged Mark Two printer and the effect of the fiber type, fiber orientations, infill density, and temperatures on tensile, fatigue, and creep properties were investigated. Carbon fiber (CF), fiberglass (FG), and Kevlar were used as reinforcing agents, and nylon as the base material. Microstructural analysis was conducted to investigate the fracture mechanism, morphology, and printing quality of the specimens. It was observed that the main failing mechanisms for CFRAM components are fiber pull-out,fiber breakage, and delamination. Further, it was understood that there is a correlation between the fiber stacking density and mechanical properties. Overall, the information provided in this study reports a unique knowledge base about the mechanical and structural behaviours of the components built with the CFRAM technology.
Tensile Properties of 3D-printed Continuous-Fiber-Reinforced Plastics
2022
Obtaining parts made of composite materials through 3D Printing Additive manufacturing have fully proved their usefulness due to several advantages such as: the possibility to directly create complex shapes without going through the classic process of transforming the semi-finished products into finished parts through technologies that consume resources and energy and are unfriendly to the environment. The main disadvantage of the parts made by 3D Printing technologies is that they are less resistant from a mechanical point of view. This can be solved by the development of 3D printers capable of printing composite parts consisting of a plastic matrix reinforced with continuous fibers. This research focuses on studying 4 types of 3D-printed Continuous-Fiber-Reinforced Plastics (CFRP) from the point of view of their mechanical properties: Onyx-rigid nylon in which micro carbon fibers are inserted and Onyx reinforced with carbon, glass or Kevlar fiber. Standardized specimens were made for the uniaxial tensile test and the experimental program was designed evaluating: the Elastic modulus [GPa], the Maximum Tensile stress [MPa], the Tensile strain at maximum Tensile stress [mm/mm]. The principal strains were also determined, using the digital image technique made using the Aramis system from GOM. The experimental tests confirm that these new materials will be serious candidates to be used in engineering applications in various fields.
Elastic properties of 3D printed fibre-reinforced structures
Composite Structures, 2018
This paper aims to evaluate the elastic properties of fibre-reinforced polymer (FRP) structures printed by three-dimensional (3D) printing technology. Both experimental and theoretical approaches are adopted to investigate the performance of FRP 3D-printed structures and predict their elastic properties. Three types of FRP materials were considered in this study including Carbon, Kevlar and Glass printed in selected arrangements of fibre filaments and Nylon matrix. An analytical model was developed based on the Volume Average Stiffness (VAS) method to predict elastic properties of 3D printed coupons, while the numerical model was developed using Abaqus to predict the failure modes and damage in the FRP 3D-printed coupons tested in this study. A parametric study was carried out to develop the mathematical expressions for calculating elastic properties of FRP 3D-printed structures. The parametric study indicates that the level of fibre reinforcements and their orientation arrangement have significant effects on the structural performance of FRP 3D-printed composite sections.
Open hole tensile testing of 3D printed continuous carbon fiber reinforced composites
Journal of Composite materials , 2020
In this study, the effects of stress concentration on the tensile properties of a 3D printed carbon fiber-nylon composite were investigated. The samples were 3D printed with continuous carbon fiber and chopped fiber reinforced nylon. Samples were manufactured with four different open hole sizes as 3. 175 mm (b in), 6.35 mm (c in), 9.25 mm (d in), and 12.7 mm (½ in). Five samples were manufactured for each hole size group. Continuous carbon fibers were printed in the longitudinal direction. Additional reinforcements were placed around the periphery of the open hole. Samples were tested under uniaxial tension. The results were compared with the prediction of fracture mechanics theories namely Average and Point Stress Criteria. The results show that failure was initiated at the stress concentration region but the progression into the hole was prevented with the presence of continuous fiber. The experimental findings show that the samples with larger holes are more sensitive to discontinuity than the ones with smaller holes. The results confirm that 3D printing can be used to strengthen the parts at the discontinuity region to mitigate the effect of stress concentration.
2021
The main objective of this study is to review existing research on the application of fused deposition modeling (FDM) for 3D printing of continuous fiber reinforced composites (CFRCs). An overview of additive manufacturing (AM) technology production techniques are provided first, followed by a look into FDM technology. The articles on CFRC printing were then summarized. The type of reinforcing material and matrix utilized, the research subject, the mechanical properties investigated, and the sample dimensions are all listed. Various pre-processing, processing, and post-processing conditions, as well as their impact on CFRC mechanical properties, were also discussed.
Composite Structures, 2021
Fused deposition modelling (FDM) is one of the most popular additive manufacturing (AM) technique which is used to investigate the elastic properties of 3D printed polyamide-based polymer composites structures. The aim of this work is to study the mechanical properties of continuous carbon fibre reinforced polyamide polymer composite samples using tensile and flexural testing by varying the fibre volume contents with applying pressure, temperature and holding the samples for 60 minutes in the platen press. The results showed that the strength and stiffness increased with the increase in fibre volume content (fraction). Hot pressed samples exhibited the increase in tensile strength by about 27 % and elastic modulus by 11 % because of increasing the fibre volume fraction from 29 % to 35%. Synergetic effect of both short and continuous carbon fibre was also studied, and it was observed that the tensile properties were higher for the samples reinforced with short and continuous fibre than only continuous fibre polymer composites. Effects of voids on 3D printed continuous carbon fibre-reinforced polymer composites were quantified. A microstructure study of the 3D printed polymer composites was carried out using scanning electron microscope (SEM). Following SEM analysis on the tested specimens, it was observed that there was a strong correlation between the mechanical properties and the microstructure. Fibre volume fraction was measured using acid digestion method to determine the amount of fibre contents before and after hot pressing (compaction). From Micro-Computed Tomography (µCT) it was confirmed that hot pressing reduced the void content which in return increased the strength and modulus.
Materials, 2022
Additively manufactured composite specimens exhibit anisotropic properties, meaning that the elastic response changes with respect to orientation. Both in-plane and out-of-plane mechanical properties are important for designing purpose. Recent studies have characterised the in-plane performance. In this study, however, through-thickness tensile strength of 3D polymer composites were determined by printing of continuous carbon fibre reinforced thermoplastic polyamide-based composite, manufactured using a Markforged Two 3D printer. This paper discusses sample fabrication and geometry, adhesive used, and testing procedure. Test standards used to determine out-of-plane properties are tedious as most of the premature failures occur between the specimens and the tabs. Two types of samples were printed according to ASTM flatwise tension standard and the results were compared to determine the geometry effect on the interlaminar strength. This test method consists of subjecting the printed s...
Advanced Composites and Hybrid Materials, 2019
Three-dimensional (3D) printing is one of potential technologies for production of designable complex filled structures and mechanical strengthening along the reinforcing fibers for composites. The objective of this paper is to study the tensile mechanical behavior of diverse concentric fiber rings and fiber layers using glass fiber (GF), Kevlar fiber (KF), and carbon fiber (CF) printed into polymer composites and then to compare them. Additionally, it also aims to identify the influence of complex filled structures of Nylon on different fiber printed polymer composites. Tensile tests and scanning electron microscope (SEM) were utilized to characterize the 3D printed composites. Results revealed that CF-printed composite exhibits the greatest tensile strength of 110 MPa and modulus of 3941 MPa as compared to glass and Kevlar fiber composites. Increase of concentric fiber rings and fiber layers is attributed to increase in tensile strength and modulus. Also, the rectangular filled structure of Nylon declared the highest tensile strength and modulus than hexagonal and triangular filled structure owing to its rectangular filling that bears maximum load in longitudinal direction.
Additive Manufacturing
The use of additive manufacturing (AM) is rapidly expanding in many industries mostly because of the flexibility to manufacture complex geometries. Recently, a family of technologies that produce fiber reinforced components has been introduced, widening the options available to designers. AM fiber reinforced composites are characterized by the fact that process related parameters such as the amount of reinforcement fiber, or printing architecture, significantly affect the tensile properties of final parts. To find optimal structures using new AM technologies, guidelines for the design of 3D printed composite parts are needed. This paper presents an evaluation of the effects that different geometric parameters have on the tensile properties of 3D printed composites manufactured by fused filament fabrication (FFF) out of continuous and chopped carbon fiber reinforcement. Parameters such as infill density and infill patterns of chopped composite material, as well as fiber volume fraction and printing architecture of continuous fiber reinforcement (CFR) composites are varied. The effect of the location of the initial deposit point of reinforcement fibers on the tensile properties of the test specimens is studied. Also, the effect that the fiber deposition pattern has on tensile performance is quantified. Considering the geometric parameters that were studied, a variation of the Rule of Mixtures (ROM) that provides a way to estimate the elastic modulus of a 3D printed composite is proposed. Findings may be used by designers to define the best construction parameters for 3D printed composite parts.