Effect of Fiber Direction & Density on Mechanic Behavior of Robotic 3D Printed Composites

2022 ◽  
Vol 11 (1) ◽  
pp. 1-8
Author(s):  
Ahmet İpekçi ◽  
Bülent Ekici
Keyword(s):  
Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3944 ◽  
Author(s):  
Zhen Gu ◽  
Zili Gao ◽  
Wenli Liu ◽  
Yongqiang Wen ◽  
Qi Gu

Natural tissues and organs have different requirements regarding the mechanical characteristics of response. It is still a challenge to achieve biomaterials with anisotropic mechanical properties using an extracellular matrix with biological activity. We have improved the ductility and modulus of the gelatin matrix using 3D printed gelatin microfibers with different concentrations and topologies and, at the same, time achieved anisotropic mechanical properties. We successfully printed flat microfibers using partially cross-linked gelatin. We modified the 10% (w/v) gelatin matrix with microfibers consisting of a gelatin concentration of 14% (w/v), increasing the modulus to about three times and the elongation at break by 39% in parallel with the fiber direction. At the same time, it is found that the microfiber topology can effectively change the matrix ductility, and changing the modulus of the gelatin used in the microfiber can effectively change the matrix modulus. These findings provide a simple method for obtaining active biological materials that are closer to a physiological environment.


2019 ◽  
Vol 290 ◽  
pp. 04002 ◽  
Author(s):  
Cătălin G. Amza ◽  
Aurelian Zapciu ◽  
Arnheiður Eyþórsdóttir ◽  
Auðbjörg Björnsdóttir ◽  
Jonathan Borg

3D printed specimens (ASTM D638 Type I) were manufactured from ABS and ASA material via additive manufacturing through material extrusion 3D printing (ME3DP). During manufacturing, the printing process has been paused, pre-impregnated biaxial or uniaxial glass fiber mesh has been placed onto the ABS/ASA substrate and then the printing process has been resumed. The obtained composite specimens have been subjected to tensile strength testing and results have been compared to those of specimens printed from homogenous material. The influence of raster angle, glass fiber direction and mesh density on resulting toughness has also been analyzed. It was found that inserting uniaxial glass fiber increases toughness of specimens in the axial direction, with a drop in layer adhesion if biaxial fiber is used. Test specimens manufactured with 30 uniaxial fiber strands embedded in a 0o raster angle 3D printed thermoplastic matrix match mechanical characteristics of injection-molded parts. The maximum mesh density without leading to delamination is one layer of glass fiber every two layers of thermoplastic matrix.


2021 ◽  
Vol 11 (23) ◽  
pp. 11315
Author(s):  
Clarissa Becker ◽  
Hannes Oberlercher ◽  
Rosmarie Brigitte Heim ◽  
Günter Wuzella ◽  
Lisa-Marie Faller ◽  
...  

The material properties of 3D printed continuous fiber composites have been studied many times in the last years. However, only a minimal number of samples were used to determine the properties in each of the reported studies. Moreover, reported results can hardly be compared due to different sample geometries. Consequently, the variability of the mechanical properties (from one sample to the other) is a crucial parameter that has not been well quantified yet. In the present work, the flexural properties of 3D printed continuous carbon fiber/nylon composite specimens were experimentally quantified, using batches of 15 test specimens. In order to account for the possible influence of the quality of the prepreg filaments on the observed variability, three different filament rolls were used to manufacture the different batches. Also, two configurations were tested, with a fiber direction parallel (longitudinal) or perpendicular (transverse) to the main axis of the specimens. The results show moderate to high variabilities of the flexural modulus, flexural strength and maximum strain. The coefficient of variation was more than twice as high in the transverse case as in the longitudinal case.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 298
Author(s):  
Sander Rijckaert ◽  
Lode Daelemans ◽  
Ludwig Cardon ◽  
Matthieu Boone ◽  
Wim Van Paepegem ◽  
...  

Recent development in the field of additive manufacturing, also known as three-dimensional (3D) printing, has allowed for the incorporation of continuous fiber reinforcement into 3D-printed polymer parts. These fiber reinforcements allow for the improvement of the mechanical properties, but compared to traditionally produced composite materials, the fiber volume fraction often remains low. This study aims to evaluate the in-nozzle impregnation of continuous aramid fiber reinforcement with glycol-modified polyethylene terephthalate (PETG) using a modified, low-cost, tabletop 3D printer. We analyze how dimensional printing parameters such as layer height and line width affect the fiber volume fraction and fiber dispersion in printed composites. By varying these parameters, unidirectional specimens are printed that have an inner structure going from an array-like to a continuous layered-like structure with fiber loading between 20 and 45 vol%. The inner structure was analyzed by optical microscopy and Computed Tomography (µCT), achieving new insights into the structural composition of printed composites. The printed composites show good fiber alignment and the tensile modulus in the fiber direction increased from 2.2 GPa (non-reinforced) to 33 GPa (45 vol%), while the flexural modulus in the fiber direction increased from 1.6 GPa (non-reinforced) to 27 GPa (45 vol%). The continuous 3D reinforced specimens have quality and properties in the range of traditional composite materials produced by hand lay-up techniques, far exceeding the performance of typical bulk 3D-printed polymers. Hence, this technique has potential for the low-cost additive manufacturing of small, intricate parts with substantial mechanical performance, or parts of which only a small number is needed.


Author(s):  
Kaiyue Deng ◽  
Hamid Khakpour Nejadkhaki ◽  
Felipe M. Pasquali ◽  
Anosh P. Amaria ◽  
Jason N. Armstrong ◽  
...  

Abstract A model to compute the elastic modulus and tensile properties of 3D printed Carbon Fiber Reinforced Polymers (CFRP) is presented. The material under consideration is Carbon Fiber Reinforced Nylon (CFRN) produced in a Fused Deposition Modeling (FDM) process. A relationship between the nylon raster in each layer and the carbon fiber volume fraction was devised with the help of a scanning electron microscope (SEM). Thirteen groups with different layer configurations and carbon-fiber percentages were formulated and tested to obtain the elastic modulus and tensile strength. This study focused only on the properties along the printed fiber direction. The results from these tests were analyzed within the rule of mixtures framework. The results suggest that the rule of mixtures can be successfully applied to unidirectional CFRP fabricated using additive manufacturing.


2016 ◽  
Vol 77 (S 02) ◽  
Author(s):  
Hassan Othman ◽  
Sam Evans ◽  
Daniel Morris ◽  
Saty Bhatia ◽  
Caroline Hayhurst

2019 ◽  
Author(s):  
Avital Perry ◽  
Soliman Oushy ◽  
Lucas Carlstrom ◽  
Christopher Graffeo ◽  
David Daniels ◽  
...  

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