Open hole tensile testing of 3D printed parts using in-house fabricated PLA filament

2020 ◽  
Vol 26 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Harshit K. Dave ◽  
Ashish R. Prajapati ◽  
Shilpesh R. Rajpurohit ◽  
Naushil H. Patadiya ◽  
Harit K. Raval

Purpose Fused deposition modeling (FDM) is being increasingly used in automotive and aerospace industries because of its ability to produce specimens having difficult geometrical shape. However, owing to lack of critical information regarding the reliability and mechanical properties of FDM-printed parts at various designs, the use of 3D printed parts in these industries is limited. Therefore, the purpose of this paper is to investigate the impact of process parameters of FDM on the tensile strength of open-hole specimen printed using in-house-fabricated polylactic acid (PLA). Design/methodology/approach In the present study, three process parameters, namely, raster angle, layer thickness and raster width, are selected for investigation of tensile strength. To produce the tensile specimens in the FDM machine, the PLA filament is used which is fabricated from PLA granules using a single-screw extruder. Further, the experimental values are measured and critically analysed. Failure modes under tests are studied using scanning electron microscopy (SEM). Findings Results indicate that the raster angle has a significant effect on the tensile strength of open-hole tensile specimen. Specimens built with 0° raster angle, 200-µm layer thickness and 500-µm raster width obtained maximum tensile strength. Originality/value In this work, a new concept of testing a plate that has a rectangular shape and a circular hole at the centre is tested. Open-hole tensile test standard ASTM D5766 has been implemented for the first time for the FDM process.

2019 ◽  
Vol 16 (4) ◽  
pp. 550-559 ◽  
Author(s):  
Abhinav Chadha ◽  
Mir Irfan Ul Haq ◽  
Ankush Raina ◽  
Rana Ratna Singh ◽  
Narendra Babu Penumarti ◽  
...  

Purpose This paper aims to explore the effect of bed temperature, primary layer thickness and infill pattern (rectilinear, honeycomb, triangular) on the mechanical properties of tensile strength and bending strength of 3D printed parts. Design/methodology/approach Samples in accordance to various ASTM standards were printed by fused deposition modelling (FDM) method by varying the various input paramaters such as bed temperature, primary layer thickness and infill pattern (rectilinear, honeycomb, triangular). Tensile and bending testing was carried out on the printed parts, and post to the testing, fractography has been carried out using scanning electron microscope. Findings With increase in bed temperature tensile strength and flexural strength first increases then decreases. With the increase in primary layer thickness, tensile strength and flexural strength increase. With regard to infill patterns, triangular and honeycomb exhibit better tensile strength and better flexural strength. Practical implications The 3D printing is increasingly becoming important for manufacturing of engineering parts, determining the process parameters which could result in better mechanical and physical properties shall certainly help designers and manufacturers globally. Originality/value This work elucidates the effect of various process parameters of FDM on tensile and flexural properties of the samples.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Debashis Mishra ◽  
Anil Kumar Das

PurposeThe purpose of the experimental investigation was to optimize the process parameters of the fused deposition modeling (FDM) technique. The optimization of the process was performed to identify the relationship between the chosen factors and the tensile strength of acrylonitrile butadiene styrene (ABS) and carbon fiber polylactic acid (PLA) thermoplastic material, FDM printed specimens. The relationship was demonstrated by using the linear experimental model analysis, and a prediction expression was established. The developed prediction expression can be used for the prediction of tensile strength of selected thermoplastic materials at a 95% confidence level.Design/methodology/approachThe Taguchi L9 experimental methodology was used to plan the total number of experiments to be performed. The process parameters were chosen as three at three working levels. The working range of chosen factors was the printing speed (60, 80 and 100mm/min), 40%, 60% and 80% as the infill density and 0.1mm, 0.2mm and 0.3mm as the layer thickness. The fused deposition modeling process parameters were optimized to get the maximum tensile strength in FDM printed ABS and carbon fiber PLA thermoplastic material specimens.FindingsThe optimum condition was achieved by the process optimization, and the desired results were obtained. The maximum desirability was achieved as 0.98 (98%) for the factors, printing speed 100mm/min, infill density 60mm and layer thickness 0.3mm. The strength of the ABS specimen was predicted to be 23.83MPa. The observed strength value was 23.66MPa. The maximum desirability was obtained as 1 (100%) for the factors, printing speed 100mm/min, infill density 60mm and layer thickness 0.2mm. The strength of the carbon fiber PLA specimen was predicted to be 26.23MPa, and the obtained value was 26.49MPa.Research limitations/implicationsThe research shows the useful process parameters and their suitable working conditions to print the tensile specimens of the ABS and carbon fiber PLA thermoplastics by using the fused deposition modeling technique. The process was optimized to identify the most influential factor, and the desired optimum condition was achieved at which the maximum tensile strength was reported. The produced prediction expression can be used to predict the tensile strength of ABS and carbon fiber PLA filaments.Practical implicationsThe results obtained from the experimental investigation are useful to get an insight into the FDM process and working limits to print the parts by using the ABS and carbon fiber PLA material for various industrial and structural applications.Social implicationsThe results will be useful in choosing the suitable thermoplastic filament for the various prototyping and structural applications. The products that require freedom in design and are difficult to produce by most of the conventional techniques can be produced at low cost and in less time by the fused deposition modeling technique.Originality/valueThe process optimization shows the practical exposures to state an optimum working condition to print the ABS and carbon fiber PLA tensile specimens by using the FDM technique. The carbon fiber PLA shows better strength than ABS thermoplastic material.


2018 ◽  
Vol 24 (8) ◽  
pp. 1317-1324 ◽  
Author(s):  
Shilpesh R. Rajpurohit ◽  
Harshit K. Dave

PurposeThe purpose of this paper to study the tensile strength of the fused deposition modelling (FDM) printed PLA part. In recent times, FDM has been evolving from rapid prototyping to rapid manufacturing where parts fabricated by FDM process can be directly used for application. However, application of FDM fabricated part is significantly affected by poor and anisotropic mechanical properties. Mechanical properties of FDM part can be improved by proper selection of process parameters.Design/methodology/approachIn the present study, three process parameter, namely, raster angle, layer height and raster width, have been selected to study their effect on tensile properties. Parts are fabricated as per ASTM D638 Type I standard.FindingsIt has been observed that the highest tensile strength obtained at 0° raster angle. Lower value of layer height is observed to be good for higher tensile strength because of higher bonding area between the layers. At higher value of raster width, tensile strength is improved up to certain extent after which presence of void reduces the tensile strength.Originality/valueIn the present investigation, layer height and raster width have been also varied along with raster angle to study their effect on the tensile strength of FDM printed PLA part.


2017 ◽  
Vol 23 (5) ◽  
pp. 943-953 ◽  
Author(s):  
Anthony A. D’Amico ◽  
Analise Debaie ◽  
Amy M. Peterson

Purpose The aim of this paper is to examine the impact of layer thickness on irreversible thermal expansion, residual stress and mechanical properties of additively manufactured parts. Design/methodology/approach Samples were printed at several layer thicknesses, and their irreversible thermal expansion, tensile strength and flexural strength were determined. Findings Irreversible thermal strain increases with decreasing layer thickness, up to 22 per cent strain. Tensile and flexural strengths exhibited a peak at a layer thickness of 200 μm although the maximum was not statistically significant at a 95 per cent confidence interval. Tensile strength was 54 to 97 per cent of reported values for injection molded acrylonitrile butadiene styrene (ABS) and 29 to 73 per cent of those reported for bulk ABS. Flexural strength was 18 to 41 per cent of reported flexural strength for bulk ABS. Practical implications The large irreversible thermal strain exhibited that corresponding residual stresses could lead to failure of additively manufactured parts over time. Additionally, the observed irreversible thermal strains could enable thermally responsive shape in additively manufactured parts. Variation in mechanical properties with layer thickness will also affect manufactured parts. Originality/value Tailorable irreversible thermal strain of this magnitude has not been previously reported for additively manufactured parts. This strain occurs in parts made with both high-end and consumer grade fused deposition modeling machines. Additionally, the impact of layer thickness on tensile and flexural properties of additively manufactured parts has received limited attention in the literature.


2015 ◽  
Vol 21 (5) ◽  
pp. 604-617 ◽  
Author(s):  
Antonio Lanzotti ◽  
Marzio Grasso ◽  
Gabriele Staiano ◽  
Massimo Martorelli

Purpose – This study aims to quantify the ultimate tensile strength and the nominal strain at break (ɛf) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper (Rep-Rap) 3D printer, by varying three important process parameters: layer thickness, infill orientation and the number of shell perimeters. Little information is currently available about mechanical properties of parts printed using open-source, low-cost 3D printers. Design/methodology/approach – A computer-aided design model of a tensile test specimen was created, conforming to the ASTM:D638. Experiments were designed, based on a central composite design. A set of 60 specimens, obtained from combinations of selected parameters, was printed on a Rep-Rap Prusa I3 in PLA. Testing was performed using a JJ Instruments – T5002-type tensile testing machine and the load was measured using a load cell of 1,100 N. Findings – This study investigated the main impact of each process parameter on mechanical properties and the effects of interactions. The use of a response surface methodology allowed the proposition of an empirical model which connects process parameters and mechanical properties. Even though results showed a high variability, additional ideas on how to understand the impact of process parameters are suggested in this paper. Originality/value – On the basis of experimental results, it is possible to obtain practical suggestions to set common process parameters in relation to mechanical properties. Experiments discussed in the present paper provide a variety of data and insight regarding the relationship among the main process parameters and the stiffness and strength of fused deposition modeling-printed parts made from PLA. In particular, this paper underlines the shortage in existing literature concerning the impact of process parameters on the elastic modulus and the strain to failure for the PLA. The experimental data produced show a good degree of compliance with analytical formulations and other data found in literature.


2020 ◽  
Vol 26 (10) ◽  
pp. 1687-1700
Author(s):  
Mozhgan Sayanjali ◽  
Amir Masood Rezadoust ◽  
Foroud Abbassi Sourki

Purpose This paper aims to focus on the development of the three-dimensional (3D) printing filaments based on acrylonitrile butadiene styrene (ABS) copolymer and styrene-ethylene/butylene-styrene (SEBS) block copolymer, with tailored viscoelastic properties and controlled flow during the 3D printing process. Design/methodology/approach In this investigation, ABS was blended with various amounts of SEBS via a melt mixing process. Then the ABS/SEBS filaments were prepared by a single-screw extruder and printed by the FDM method. The rheological properties were determined using an MCR 501 from Anton-Paar. The melt flow behavior of ABS/SEBS filaments was determined. The morphology of the filaments was studied by scanning electron microscope and the mechanical (tensile and impact) properties, surface roughness and void content of printed samples were investigated. Findings The rheological results can accurately interpret what drives the morphology and mechanical properties’ changes in the blends. The impact strength, toughness, elongation-at-break and anisotropy in mechanical properties of ABS samples were improved concurrently by adding 40 Wt.% of SEBS. The optimal tensile properties of blend containing 40 Wt.% SEBS samples were obtained at −45°/+45° raster angle, 0.05 mm layer thickness and XYZ build orientation. Optimized samples showed an 890% increase in elongation compared to neat ABS. Also, the impact strength of ABS samples showed a 60% improvement by adding 40 Wt.% SEBS. Originality/value The paper simultaneously evaluates the effects of material composition and 3D printing parameters (layer thickness, raster angle and build orientation) on the rheology, morphology, mechanical properties and surface roughness. Also, a mechanical properties comparison between printed samples and their compression-molded counterpart was conducted.


2017 ◽  
Vol 23 (6) ◽  
pp. 998-1010 ◽  
Author(s):  
Omar Ahmed Mohamed ◽  
Syed Hasan Masood ◽  
Jahar Lal Bhowmik

Purpose The purpose of this paper is to investigate the effect of process parameters of fused deposition modelling (FDM) 3D printing process on viscoelastic responses (creep compliance and recoverable compliance) of FDM built parts using a novel experimental design technique. Design/methodology/approach As part of the process characterization, a recently developed class of three-level design methodology – definitive screening design (DSD) – was used in this study to fit a second-order polynomial regression model. Artificial neural network (ANN) was also used to determine the optimal process parameters to improve creep compliance and recoverable compliance. The relationship between layer thickness, air gap, raster angle, build orientation, road width, number of contours and creep performance of FDM fabricated part was thereafter established empirically. Scanning electron microscope (SEM) is used to examine and characterize the morphology of the structures for some samples. Findings This study found that the creep resistance of FDM-manufactured part is significantly influenced by layer thickness, air gap, raster angle and number of contours and it can be improved by optimizing the settings of the selected parameters. The relationship between FDM process parameters and creep properties was determined, with the best creep performance observed by using 0.127 mm of layer thickness, zero air gap, zero raster angle, build orientation of 17.188°, road width of 0.4572 mm and 10 contours. Finally, the result is verified by confirmation experiments. The results prove that a DSD is a very effective design in characterizing the influence of process parameters on creep properties of FDM-built part at the lowest cost. Originality/value The originality of this paper lies in characterizing and optimizing the effect of process parameters on creep performance of FDM manufactured part that has not been studied in all previous studies. The paper highlights, for the first time, how the application of DSD can overcome most of the limitations encountered in the conventional techniques. This study can be used as a guide to the different additive manufacturing users of various industries and the results provide a good technical database on how FDM process parameters influence the creep performance of manufactured parts.


2020 ◽  
Vol 26 (10) ◽  
pp. 1733-1738
Author(s):  
André Luiz Alves Guimarães ◽  
Vicente Gerlin Neto ◽  
Cesar Renato Foschini ◽  
Maximiliano dos Anjos Azambuja ◽  
Luiz Antonio Vasques Hellmeister

Purpose The purpose of this paper is to investigate and discuss the influence of printing parameters on the mechanical properties of acrylonitrile butadiene styrene (ABS) print by fused deposition modelling (FDM). The mechanical properties of ABS are highly influenced by printing parameters, and they determine the final product quality of printed pieces. Design/methodology/approach For the paper’s purpose, five main parameters (extrusion temperature, infill pattern, air gap, printing speed and layer thickness) were selected and varied during ABS printing on an open-source and self-replicable FDM printer. Three different colors of commercially available ABS were also used to investigate color and printing parameter’s influence on the tensile strength. Findings The research results suggest that two parameters (infill pattern and layer thickness) were most influential on the mechanical properties of print ABS, being able to enhance its tensile strength. Another key influential factor was material color selected prior to printing, which influenced the tensile strength of the print specimen. Originality/value This study provides information on print parameters’ influence on the tensile strength of ABS print on replicable open-source three-dimensional (3D) printers. It also suggests the influence of materials’ color on print pieces’ tensile strength, indicating a new parameter for materials selection for 3D printing.


2014 ◽  
Vol 592-594 ◽  
pp. 1075-1079 ◽  
Author(s):  
Swayam Bikash Mishra ◽  
Siba Sankar Mahapatra

Fused Deposition Modeling (FDM) is one of the efficient rapid prototyping (RP) technologies that forms 3D objects by adding material layer by layer from CAD generated solid models. However, the FDM built part is hardly anisotropic in nature due to layer-by-layer build mechanism. Literature suggests that mechanical property, especially tensile strength, of FDM built part is severely affected by process parameters. Among all the parameters, contour number happens to be an important parameter because it reduces stress concentration resulting in avoidance of premature breakdown. Therefore, in this work contour number along with five important process parameters such as layer thickness, raster width, part orientation, raster angle and air gap are considered and their effect on tensile strength of FDM built parts is studied. Experiments are conducted using Face Centred Central Composite Design (FCCCD) in order to reduce the experimental runs. An optimal parameter setting has been suggested for the maximisation of tensile strength of the FDM built parts.


2021 ◽  
Author(s):  
Mobina Movahedi

Additive manufacturing (AM), 3D printing, is defined as a process of depositing materials layer by layer to create three-dimensional printed models, as opposed to subtractive manufacturing methodologies. It has the potential of revolutionizing field of manufacturing, which allows us to create more complex geometries with lower cost and faster speed in comparison to injection molding, compression forming, and forging. Therefore, 3D printing can shorten the design manufacturing cycle, reduce the production cost, and increase the competitiveness. Due to the improvements of processes and advancements of modeling and design, Fused Deposition Modeling (FDM) technologies, a common 3D printing technique, have been involved in wide various applications in the past three decades and numerous studies have been gathered. This research work studies directional properties of FDM 3D printed thermoplastic parts per ASTM D638. Tensile strength and modulus of the coupons along and perpendicular to the printing direction are evaluated. It is observed that FDM 3D printing introduces anisotropic behavior to the manufactured part, e.g. tensile strength of 57.7 and 30.8 MPa for loading along and perpendicular to the printing direction, respectively. FDM 3D printers are not ideal and introduce defects into the manufactured parts, e.g. in the form of missing material, gap. This study investigates the impact of gaps on tensile strength and modulus of 3D printed parts. A maximum reduction of 20% in strength is found for a gap (missing bead) along the loading direction.


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