A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract Abstract Tensile strength, modulus of rupture, and impact resistance were found for different layer orientations of ABS rapid prototype solid models. The samples were fabricated by a Stratasys rapid prototyping machine in five different layer orientations. The 0° orientation where layers were deposited along the length of the samples displayed superior strength and impact resistance over all the other orientations. The anisotropic properties were probably caused by weak interlayer bonding and interlayer porosity. <s> BIB001 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Rapid Prototyping (RP) technology has been advanced to fabricate initial prototypes from various materials. Stratasys’ Fused Deposition Modeling (FDM) is one of the typical RP processes that provide functional prototypes of ABS plastic. In order to predict the behavior of final ABS parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on composite material properties. In this paper, we seek t the properties of ABS parts fabricated by the FDM 1650. Using the Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths of crisscross specimens, [45 °/-45°], cross specimens, [0 °/90°], and directionally fabricated tensile specimens ([0°] and [90 °]) were measured and compared with the injection molded FDMABS P400 material. For the FDM parts made with a –0.003” air gap, the typical tensile strength ranged between 65 percent and 72 percent of the strength of injection molded ABS P400. From the experiment s, several build rules for designing FDM parts were obtained. <s> BIB002 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Purpose – The following research seeks to focus on optimizing the fused deposition modeling (FDM) process of RP systems.Design/methodology/approach – Early stages of this study are based on the Taguchi method in establishing rapid prototyping building factors and their various levels. The ultimate tensile strength, dimension accuracy and surface roughness (SR), are analyzed. Through analysis of variance (ANOVA) and contribution approximation, significant building factors of each quality characteristic and optimal factors level combinations of each best quality characteristic are obtained. The main steps are setting the weight for each quality characteristic of the previous Taguchi method, obtaining the estimated multiple building quality characteristics through integrating the Gray theory, and obtaining a set of optimal building factors. Finally, the result is verified by the Gray theory and the technique for order preference by similarity to ideal solution (TOPSIS) evaluation method.Findings – It is prov... <s> BIB003 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Fused deposition modelling (FDM) is a fast growing rapid prototyping (RP) technology due to its ability to build functional parts having complex geometrical shapes in reasonable build time. The dimensional accuracy, surface roughness, mechanical strength and above all functionality of built parts are dependent on many process variables and their settings. In this study, five important process parameters such as layer thickness, orientation, raster angle, raster width and air gap have been considered to study their effects on three responses viz., tensile, flexural and impact strength of test specimen. Experiments have been conducted using central composite design (CCD) and empirical models relating each response and process parameters have been developed. The models are validated using analysis of variance (ANOVA). Finally, bacterial foraging technique is used to suggest theoretical combination of parameter settings to achieve good strength simultaneously for all responses. <s> BIB004 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Fused deposition modelling (FDM) is a fast growing rapid prototyping (RP) technology due to its ability to build functional parts having complex geometrical shape in reasonable time period. The quality of built parts depends on many process variables. In this study, five important process parameters such as layer thickness, orientation, raster angle, raster width and air gap are considered. Their influence on three responses such as tensile, flexural and impact strength of test specimen is studied. Experiments are conducted based on central composite design (CCD) in order to reduce experimental runs. Empirical models relating response and process parameters are developed. The validity of the models is tested using analysis of variance (ANOVA). Response surface plots for each response is analysed and optimal parameter setting for each response is determined. The major reason for weak strength may be attributed to distortion within or between the layers. Finally, concept of desirability function is used for maximizing all responses simultaneously. <s> BIB005 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Rapid prototyping (RP) fulfills the current need in manufacturing industry to shorten the design cycle while improving its quality. Since there are various methods of RP process, this study focuses on the mechanical properties and microstructure of fused deposition modeling (FDM) RP specimens between two types of raster orientation which are cross (0°/90°) and crisscross (45°/−45°).The method of investigation in order to compare the result is done by doing several tests. The tests conducted throughout the research are; tensile, bending, impact and deflection test. The material used is Acrylonitrile Butadiene Styrene (ABS): a terpolymer of acrylonitrile, butadiene and styrene. The findings from this research are used to evaluate which parameters give the best result and performance besides improving the quality of a design for better product development. <s> BIB006 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract The Fused Deposition Modelling process is a highly efficient Rapid Prototyping approach that makes it possible to rapidly generate even much complicated parts. Unfortunately, the Fused Deposition Modelling is affected by several parameters, whose setting may have a strong impact on the components strength. This paper is devoted to the study of the effects generated by the Fused Deposition Modelling production parameters on the tensile strength and on the stiffness of the generated components, tackling the question from both the experimental and the numerical points of view. For this purpose, an analytical model was developed, which is able to predict the strength and the stiffness properties, based on the number of contours deposited around the component edge and on the setting of the other main parameters of the deposition process. The fundamental result of the paper consists in the possibility of predicting the mechanical behaviour of the Fused Deposition modelled parts, once the raster pattern (dimensions, number of contours, raster angle) has been stated. The effectiveness of the theoretical model has been verified by comparison to a significant number of experimental results, with mean errors of about 4%. <s> BIB007 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> This paper presents the research done to determine the functional relationship between process parameters and tensile strength for the fused deposition modelling (FDM) process using the group method for data modelling for prediction purposes. An initial test was carried out to determine whether part orientation and raster angle variations affect the tensile strength. It was found that both process parameters affect tensile strength response. Further experimentations were carried out in which the process parameters considered were part orientation, raster angle, raster width and air gap. The process parameters and the experimental results were submitted to the group method of data handling (GMDH), resulting in predicted output, in which the predicted output values were found to correlate very closely with the measured values. Using differential evolution (DE), optimal process parameters have been found to achieve good strength simultaneously for the response. The mathematical model of the response of the tensile strength with respect to the process parameters comprising part orientation, raster angle, raster width and air gap has been developed based on GMDH, and it has been found that the functionality of the additive manufacturing part produced is improved by optimizing the process parameters. The results obtained are very promising, and hence, the approach presented in this paper has practical application for the design and manufacture of parts using additive manufacturing technologies. <s> BIB008 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract Fused deposition modeling (FDM) is a fast growing rapid prototyping (RP) technology due to its ability to build functional parts having complex geometrical shapes in reasonable build time. The literature reveals that the properties of RP built parts such as surface roughness, strength, dimensional accuracy, build cost, etc are related to and can be improved by the appropriate settings of the input process parameters. However, it is difficult to obtain an adequate strength for some applications due to the characteristics of the process. This paper, proposes particle swarm optimization (PSO) technique to suggest theoretical combination of parameter settings to achieve good strength simultaneously for all responses. Genetic Programming (GP) is used to approximate the relationship between process parameters (Layer thickness, Raster angle, Raster width and Air gap) and the Tensile strength that can withstand the part. The performance of the proposed method is compared with Differential Evolution (DE) algorithm in terms of prediction accuracy and convergence characteristics. Results show the potential of the both algorithm used for, but DEA gives better result than PSO. <s> BIB009 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Purpose – The mechanical properties and surface finish of functional parts are important consideration in rapid prototyping, and the selection of proper parameters is essential to improve manufacturing solutions. The purpose of this paper is to describe how parts manufactured by fused deposition modelling (FDM), with different part orientations and raster angles, were examined experimentally and evaluated to achieve the desired properties of the parts while shortening the manufacturing times due to maintenance costs. Design/methodology/approach – For this purpose, five different raster angles (0°, 30°, 45°, 60° and 90°) for three part orientations (horizontal, vertical and perpendicular) have been manufactured by the FDM method and tested for surface roughness, tensile strength and flexural strength. Also, behaviour of the mechanical properties was clarified with scanning electron microscopy images of fracture surfaces. Findings – The research results suggest that the orientation has a more significant in... <s> BIB010 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract Building end-use functional parts with additive manufacturing (AM) technologies is a challenging task. Several factors influence their surface finish, dimensional accuracy, mechanical properties and cost. Their orientation inside the building chamber is one of the most significant factors in AM processes. When using Fused Deposition Modeling (FDM) to build such parts, additional factors must be considered. This paper aims to accomplish two purposes: finding a good model to simulate FDM parts and correlating a finite element analysis (FEA) simulation with physical testing. The first objective was achieved by experimental tensile test of specimens to determine the nine mechanical constants that defines the stiffness matrix of an orthotropic material. Three Young’s modulus, three Poisson’s ratio and three shear modulus were experimentally obtained as well as yield tensile and ultimate strength of each specimen. A simple part was designed and manufactured in different orientations to be physically tested and simulated to achieve the second objective. Polycarbonate (PC) was used as part material. Combined loading including bending and torsion was used. Differences on mechanical response were observed during the physical test of the parts depending on the building direction. Conclusions comment results and the convenience of using a different constitutive model depending on the design and use specifications. <s> BIB011 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> In this study, a preliminary effort was undertaken to represent the mechanical properties of a 3D printed specimen as a function of layer number, thickness and raster orientation by investigating the correlation between the mechanical properties of parts manufactured out of ABS using Fused Filament Fabrication (FFF) with a commercially available 3D printer, Makerbot Replicator 2x, and the printing parameters, such as layer thickness and raster orientation, were considered. Specimen were printed at raster orientation angles of 0°, 45° and 90°. Layer thickness of 0.2 mm was chosen to print specimens from a single layer to 35 layers. Samples were tested using an MTS Universal Testing Machine with extensometer to determine mechanical strength characteristics such as modulus of elasticity, ultimate tensile strength, maximum force and maximum elongation as the number of layers increased. Results showed that 0° raster orientation yields the highest mechanical properties compared to 45° and 90° at each individual layer. A linear relationship was found between the number of layers and the maximum force for all three orientations, in other words, maximum force required to break specimens linearly increased as the number of layers increased. The results also found the elastic modulus and maximum stress to increase as the number of layers increased up to almost 12 layers. For samples with more than 12 layers, the elastic modulus and maximum stress still increased, but at a much slower rate. These results can help software developers, mechanical designers and engineers reduce manufacturing time, material usage and cost by eliminating unnecessary layers that do not increase the ultimate stress of the material by improving material properties due to the addition of layers.Copyright © 2015 by ASME <s> BIB012 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> This paper discusses optimization studies on process parameters for fused deposition modelling (FDM). Layer thickness, Orientation angle and fill angle are the process variables considered for optimization. Ultimate tensile strength, surface roughness, dimensional accuracy and manufacturing time were considered as response parameters. Experiments were designed using well known Taguchi's L9 orthogonal array, Taguchi's S/N ratio was used to identify optimum parameter values. Effectiveness of each parameter was investigated using analysis of variance. Furthur, performance of optimum conditions were validated by conducting verification experiment. <s> BIB013 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract As the number of prosumer printers has expanded rapidly, they now make up the majority of the 3-D printer market and of these printers those in the open-source lineage of the RepRap also have expanded to dominate. Although still primarily used for prototyping or hobbyist production of low-value products, the RepRap has the capacity to be used for high-value distributed manufacturing. A recent study found that RepRap printed parts printed in realistic environmental conditions can match and even out perform commercial 3-D printers using proprietary FDM in terms of tensile strength with the same polymers. However, tensile strengths of the large sample set of RepRap prints fluctuated. In order to explain that fluctuation and better inform designers on RepRap print properties this study determines the effect of color and processing temperature on material properties of Lulzbot TAZ deposited PLA in various colors. Five colors (white, black, blue, gray, and natural) of commercially available filament processed from 4043D PLA is tested for crystallinity with XRD, tensile strength following ASTM D638 and the microstructure is evaluated with environmental scanning electron microscope. Results are presented showing a strong relationship between tensile strength and percent crystallinity of a 3-D printed sample and a strong relationship between percent crystallinity and the extruder temperature. Conclusions are drawn about the effects of color and processing temperature on the material properties of 3-D printed PLA to promote the open-source development of RepRap 3-D printing. <s> BIB014 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Purpose ::: ::: ::: ::: ::: This paper aims to present the influences of several production variables on the mechanical properties of specimens manufactured using fused deposition modeling (FDM) with polylactic acid (PLA) as a media and relate the practical and experimental implications of these as related to stiffness, strength, ductility and generalized loading. ::: ::: ::: ::: ::: Design/methodology/approach ::: ::: ::: ::: ::: A two-factor-level Taguchi test matrix was defined to allow streamlined mechanical testing of several different fabrication settings using a reduced array of experiments. Specimens were manufactured and tested according to ASTM E8/D638 and E399/D5045 standards for tensile and fracture testing. After initial analysis of mechanical properties derived from mechanical tests, analysis of variance was used to infer optimized production variables for general use and for application/load-specific instances. ::: ::: ::: ::: ::: Findings ::: ::: ::: ::: ::: Production variables are determined to yield optimized mechanical properties under tensile and fracture-type loading as related to orientation of loading and fabrication. ::: ::: ::: ::: ::: Practical implications ::: ::: ::: ::: ::: The relation of production variables and their interactions and the manner in which they influence mechanical properties provide insight to the feasibility of using FDM for rapid manufacturing of components for experimental, commercial or consumer-level use. ::: ::: ::: ::: ::: Originality/value ::: ::: ::: ::: ::: This paper is the first report of research on the characterization of the mechanical properties of PLA coupons manufactured using FDM by the Taguchi method. The investigation is relevant both in commercial and consumer-level aspects, given both the currently increasing utilization of 3D printers for component production and the viability of PLA as a renewable, biocompatible material for use in structural applications. <s> BIB015 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Anisotropic mechanical properties related to build orientation is a characteristic of parts fabricated with 3D printing technologies. In the development of new materials for 3D printing processes, understanding the effects of 3D printer build orientation and raster pattern on physical property and failure mode differences is extremely important. While there is currently no standard for the evaluation of build orientation-based mechanical performance, such analysis has typically been achieved through the fabrication and scrutiny of tensile and other test coupons which were printed in different build orientations. In some cases, printing specimens in the ZXY (or vertical) build orientation can be difficult due to the capability of a given 3D printer platform. There are also multiple tensile test specimen geometries specified in the ASTM D638 standard for the tensile testing of polymer materials and understanding which specimen geometry works best for 3D printing is not currently well understood. The work presented here explores the effect of tensile test specimen geometry on the anisotropy of mechanical properties related to the build orientation of tensile test specimens. The test coupons were fabricated using a material extrusion 3D printing platform based on fused deposition modeling technology using a grade of acrylonitrile butadiene styrene not typically used in 3D printing in order to simulate the testing of a new material. The effects of raster pattern and the geometric dependence of mechanical property anisotropy were explored, and validation of the use of “faux vertical” specimens in lieu of ZXY-printed specimens was demonstrated. Finally, scanning electron microscopy was used to perform fractography on the various versions of the printed tensile test specimens in order to determine the effect of raster pattern on failure mode. <s> BIB016 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> In contrast to conventional subtractive manufacturing methods which involve removing material to reach the desired shape, additive manufacturing is the technology of making objects directly from a computer-aided design model by adding a layer of material at a time. In this study, a comprehensive effort was undertaken to represent the strength of a 3D printed object as a function of layer thickness by investigating the correlation between the mechanical properties of parts manufactured out of acrylonitrile butadiene styrene (ABS) using fused deposition modeling and layer thickness and orientation. Furthermore, a case study on a typical support frame is done to generalize the findings of the extensive experimental work done on tensile samples. Finally, fractography was performed on tensile samples via a scanning digital microscope to determine the effects of layer thickness on failure modes. Statistical analyses proved that layer thickness and raster orientation have significant effect on the mechanical properties. Tensile test results showed that samples printed with 0.2 mm layer thickness exhibit higher elastic modulus and ultimate strength compared with 0.4 mm layer thickness. These results have direct influence on decision making and future use of 3D printing and functional load bearing parts. <s> BIB017 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts having complex geometries. The mechanical properties of a built part depend on several process parameters. The aim of this study is to characterize the effect of build orientation, layer thickness and feed rate on the mechanical performance of PLA samples manufactured with a low cost 3D printer. Tensile and three-point bending tests are carried out to determine the mechanical response of the printed specimens. Due to the layer-by-layer process, 3D printed samples exhibit anisotropic behaviour. Upright orientation shows the lowest mechanical properties. On the other hand, on-edge and flat orientation show the highest strength and stiffness. From a layer thickness and feed rate point of view, it is observed that ductility decreases as layer thickness and feed rate increase. In addition, the mechanical properties increase as layer thickness increases and decrease as the feed rate increases for the upright orientation. However, the variations in mechanical properties with layer thickness and feed rate are of slight significance for on-edge and flat orientations, except in the particular case of low layer thickness. Finally, the practicality of the results is assessed by testing an evaluation structure. <s> BIB018 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract Acrylonitrile–butadiene–styrene (ABS) is one of the most widely usedindustrial thermoplastic and it is the most common material used in fused deposition modeling (FDM) technology. While FDM is one of the most used additive manufacturing (AM) technology commonly employed formodeling, prototyping, and manufacturing applications, the major research issues have been to balance ability to produce aesthetically appealinglooking products with functionality. It is therefore critical to know the mechanical properties of these parts, which, is as expected different from their nominal values.A FDM manufactured part has an internal channel referred to as infill. This internal build pattern has different mechanical properties than the same shaped part without the internal channel. This paper aims to define the effect of specimen mesostructure on the monotonic tensile behavior of ABS parts manufactured by FDM. The experiment uses the uPrint SE 3D printer to produce samples from ABS thermoplastic. The samples are tested following a modified form of ASTM D638 standard for plastic. The printed pieces are tested to failure using an Instron testing machine, and a strain gage extensometer that measures the amount of elongation in the pieces until failure. These standardized pieces are compared to know values of traditionally manufactured materials. This test shows the strength loss of materials through the 3D printing process compared to traditional manufacturing methods. The experiment for plastics is designed around two key criteria, orientation of the pieces, and the percent of infill during the printing process. It was found that a value of maximum strength, of 3D printed ABS, was approximately 92% of accepted values for the material, with a certainty of 5%. The study also shows that the bonds between layers are only 79% as strong as an axil loading along the layers. <s> BIB019 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Abstract The Additive Manufacturing (AM) technology initially was developed as a rapid prototyping tool for visualization and validation of designs. The recent development of AM technologies, such as Fused Deposition Modelling (FDM), is driving it from rapid prototyping to rapid manufacturing. However, building end-user functional parts using FDM proved to be a challenging task. The difficulty arises from the large number of processing parameters that affect the final part design such as: building direction, extrusion temperature, layer height, infill pattern and more. The processing parameters of FDM influence the quality of the parts and their functionality. In addition, a more systemic understanding is required to elaborate on the impact of the FDM processing parameters on the final part's mechanical properties, dimensional accuracy and building time. The presented paper provides an experimental study to investigate the independent effect of each processing parameter on the mechanical properties and dimensional accuracy repeatability of FDM parts. A total of 18 test specimen samples were printed using varying processing parameters. In order to investigate the repeatability and resulted tolerances, the dimensions of these specimens were measured and compared with a 3D CAD model. The presented work utilizes a tensile test per ASTM D638 standards to obtain the mechanical properties of each fabricated sample. In addition, the work provides a Finite Element Analysis (FEA) model for AM parts. The work suggested to simulate their behavior under mechanical loads for future investigation on the coupled effects of processing parameters. <s> BIB020 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> The mechanical properties of a fused deposition modeling (FDM) process product are greatly influenced by many process parameters. The identified parameters namely deposition orientation, layer thickness and deposition style, raster width, and raster gap are more significant factors contributing to the strength of a FDM product. In this paper, tensile strength, flexural strength, and impact strength are considered as three evaluation indexes to characterize the mechanical properties of a FDM part. An experimental research approach based on the Taguchi method was presented and some special specimens were designed. The influences of the five parameters on the three evaluation indexes were analyzed by the use of analysis of variance (ANOVA). Finally, based on the gray relational analysis, a set of optimal process parameter combination was obtained to optimize comprehensive mechanical properties of FDM parts. <s> BIB021 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> The purpose of this paper is to study the effects of these major parameters, including layer thickness, deposition velocity and infill rate, on product’s mechanical properties and explore the quantitative relationship between these key parameters and tensile strength of the part.,A VHX-1000 super-high magnification lens zoom three-dimensional (3D) microscope is utilized to observe the bonding degree between filaments. A temperature sensor is embedded into the platform to collect the temperature of the specimen under different parameters and the bilinear elastic-softening cohesive zone model is used to analyze the maximum stress that the part can withstand under different interface bonding states.,The tensile strength is closely related to interface bonding state, which is determined by heat transition. The experimental results indicate that layer thickness plays the predominant role in affecting bonding strength, followed by deposition velocity and the effect of infill rate is the weakest. The numerical analysis results of the tensile strength predict models show a good coincidence with experimental data under the elastic and elastic-softened interface states, which demonstrates that the tensile strength model can predict the tensile strength exactly and also reveals the work mechanism of these parameters on tensile strength quantitatively.,The paper establishes the quantitative relationship between main parameters including layer thickness, infill rate and deposition velocity and tensile strength for the first time. The numerically analyzed results of the tensile strength predict model show a good agreement with the experimental result, which demonstrates the effectiveness of this predict model. It also reveals the work mechanism of the parameters on tensile strength quantitatively for the first time. <s> BIB022 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Fused deposition modeling (FDM), a well known 3D printing technology is widely used in various sorts of industrial applications because of its ability to manufacture complex objects in the stipulated time. However, the proper selection of input process parameters in FDM is a tedious task that directly affects the part performance. Here, in this work, the research efforts have been made to optimize the FDM process parameters in order to find out the best parameter setting as per the mechanical and surface quality perspectives by using hybrid particle swarm and bacterial foraging optimization (PSO–BFO) evolutionary algorithm. Taguchi L18 orthogonal array was used for the development of acro-nitrile butadiene styrene based 3D components by considering layer thickness, support material, model interior and orientation as a process parameters. Further, the relationships among selected FDM process parameters and output responses such as hardness, flexural modulus, tensile strength and surface roughness were established by using linear multiple regression. Then, the effects of individual process parameters on selected response parameters were examined by signal to noise ratio plots. Finally, a multi-objective optimization of process parameters has been performed with hybrid PSO–BFO, general PSO and BFO algorithm, respectively. The overall results reveal that the layer thickness of 0.007 mm, support material type sparse, part orientation of 60\({^\circ }\) and model interior of high density helps in achieving desired performance level. <s> BIB023 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Fused deposition modelling (FDM) has been widely used in medical appliances, automobile, aircraft and aerospace, household appliances, toys, and many other fields. The ease of processing, low cost and high flexibility of FDM technique are strong advantages compared to other techniques for thermoelectric polymer composite fabrication. This research work focuses on the effect of two crucial printing parameters (infill density and printing pattern) on the tensile, dynamic mechanical, and thermoelectric properties of conductive acrylonitrile butadiene styrene/zinc oxide (CABS/ZnO composites fabricated by FDM technique. Results revealed significant improvement in tensile strength and Young’s modulus, with a decrease in elongation at break with infill density. Improvement in dynamic storage modulus was observed when infill density changed from 50% to 100%. However, the loss modulus and damping factor reduced gradually. The increase of thermal conductivity was relatively smaller compared to the improvement of electrical conductivity and Seebeck coefficient, therefore, the calculated figure of merit (ZT) value increased with infill density. Line pattern performed better than rectilinear, especially in tensile properties and electrical conductivity. From the results obtained, FDM-fabricated CABS/ZnO showed much potential as a promising candidate for thermoelectric application. <s> BIB024 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Compared to the common selective laser sintering (SLS) manufacturing method, fused deposition modeling (FDM) seems to be an economical and efficient three-dimensional (3D) printing method for high temperature polymer materials in medical applications. In this work, a customized FDM system was developed for polyether-ether-ketone (PEEK) materials printing. The effects of printing speed, layer thickness, printing temperature and filling ratio on tensile properties were analyzed by the orthogonal test of four factors and three levels. Optimal tensile properties of the PEEK specimens were observed at a printing speed of 60 mm/s, layer thickness of 0.2 mm, temperature of 370 °C and filling ratio of 40%. Furthermore, the impact and bending tests were conducted under optimized conditions and the results demonstrated that the printed PEEK specimens have appropriate mechanical properties. <s> BIB025 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> Rapid prototyping with FDM technology is widely used by industry for producing prototypes. High quality and low processing cost are the main concerns. This study aims to determine the optimal parameter setting of 3D printing based on FDM technology to produce prototypes with high tensile strength with low energy consumption and processing time. The parameters to be optimized are temperature, density and fill angle. The Taguchi method is used to design the expereiment. PCR-TOPSIS is used to obtain the optimal parameter settings simultaneously. The result showed that optimal parameters setting were in level combination of extrusion temperature 210°C, 40% of density and 45° of fill angle. From the three parameters, the most significant parameter is the infill density. <s> BIB026 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Tensile Strength <s> This paper presents a comparative study of the tensile mechanical behaviour of pieces produced using the Fused Deposition Modelling (FDM) additive manufacturing technique with respect to the two types of thermoplastic material most widely used in this technique: polylactide (PLA) and acrylonitrile butadiene styrene (ABS). The aim of this study is to compare the effect of layer height, infill density, and layer orientation on the mechanical performance of PLA and ABS test specimens. The variables under study here are tensile yield stress, tensile strength, nominal strain at break, and modulus of elasticity. The results obtained with ABS show a lower variability than those obtained with PLA. In general, the infill percentage is the manufacturing parameter of greatest influence on the results, although the effect is more noticeable in PLA than in ABS. The test specimens manufactured using PLA perform more rigidly and they are found to have greater tensile strength than ABS. The bond between layers in PLA turns out to be extremely strong and is, therefore, highly suitable for use in additive technologies. The methodology proposed is a reference of interest in studies involving the determination of mechanical properties of polymer materials manufactured using these technologies. <s> BIB027
Tensile strength is one of the most analyzed mechanical properties. In most of the papers, the parts for the tensile test were produced according to the American Standard for Testing and Materials (ASTM) D638 standard. This standard is used for testing the tensile properties of thermoplastics. The test specimens were dumbbell-shaped. Some of the recent work is summarized below. Montero et al. BIB002 investigated five process parameters (air gap, raster width, extrusion temperature, filament color, and raster orientation) and designed their experiment according to fractional factorial design. Their printed specimens were produced from ABS using a Stratasys FDM 1650 machine. The experimental results showed that the air gap and raster orientation were two significant parameters for tensile strength, and a negative air gap and 0 • raster orientation were preferable for maximum tensile strength. Es-Said et al. BIB001 analyzed the tensile properties of ABS parts manufactured by the FDM process by considering raster orientation as the variable. For this, ABS parts were produced for five different raster orientations. Like other research, it was shown that a raster orientation of 0 • was best to maximize the tensile strength. Along with surface roughness and dimensional accuracy, Wang et al. BIB003 also analyzed the impact of the six parameters on tensile strength, and showed that build orientation in the Z-direction was the most significant parameter for the tensile strength property. Layer thickness, build orientation, raster width, raster orientation, and air gap were considered as variables to examine their impact on tensile strength by Panda et al BIB004 . Their experiment was designed according to FCCCD, and a quadratic equation was formulated for the tensile property. They showed that all parameters (other than raster width), and the combinations of parameters were influential for tensile strength. Bagsik et al.  , Domingo-Espin et al. BIB011 , and Letcher et al. BIB012 tested the tensile strength of Ultem 9085, PC, and ABS parts, respectively, in different build orientations. The first two groups of researchers showed that tensile strength was maximum when build orientation was 0 • in the X-direction, but the outcome of the third group's experimental study was different. In separate research, Hernandez et al.  showed that the influence of build orientation was not significant for the tensile strength of ABS P430 built parts. The influence of five process parameters (layer thickness, build orientation, raster orientation, raster width, and air gap) on tensile strength was studied by Sood et al. BIB005 . Their parts were built by an FDM machine according to FCCCD; a quadric equation for tensile strength was formulated using the response surface method, and ANOVA was used to determine the significance of different terms in the equation. It was shown that all parameters, excluding raster width, and the interactions of different parameters were significant. They also plotted response surface graphs to visualize the change of tensile strength with the interaction between two parameters. Fatimatuzahraa et al. BIB006 investigated the impact of raster orientation on the mechanical properties, including tensile strength, of ABS parts. Three parts, each having four different raster orientations, were produced, and parts were tested by a destructive tensile testing machine. The results concluded that tensile strength was maximum and almost the same at the cross (0 • /90 • ) and crisscross (45 • /−45 • ) raster orientations. Croccolo et al. BIB007 analyzed the impact of the number of shells on the tensile strength, and showed that the property increases with the increase in the number of shells. Rayegani et al. BIB008 investigated five process parameters (layer thickness, build orientation, raster orientation, raster width, and air gap) to get an optimum combination of the process parameters that maximize the tensile strength of ABS printed parts. For this purpose, the group method of data handling (GMDH) approach was used to develop a mathematical model that related process parameters with tensile strength. In order to maximize tensile strength, a differential evolution (DE) optimization approach was applied to get levels of each parameter. The optimization results showed that tensile strength approached a maximum at the minimum setting of layer thickness, build orientation, raster width, and negative air gap. Raster orientation was found to be comparatively less significant. On the other hand, Panda et al. BIB009 also used DE to get an optimum combination of process parameters for tensile strength. However, the combination of process parameters (high layer thickness, raster width, and positive air gap) was different from the combination obtained by Rayegani et al. BIB008 . Durgun et al. BIB010 analyzed the impact of build orientation and raster orientation on tensile properties. Their experimental investigation results suggested that 0 • raster orientation and 0 • build orientation were suitable to optimize tensile strength. Build orientation was found to be more significant than raster orientation. Gorski  analyzed the importance of build orientation on tensile strength and the brittleness property of FDM built ABS parts. The author showed that tensile strength was maximum at 0 • build orientation. However, the FDM built part became brittle when the build orientations exceeded 20 • in the X-axis and 25 • in the Y-axis. Wu et al.  showed that layer thickness and raster orientation were both significant for the tensile properties of PEEK parts. Additionally, the authors also compared PEEK with ABS, and the comparison outcome was that PEEK parts performed better under tensile loading when compared to ABS parts. However, for both materials, the mechanical properties of the FDM parts were worse than injection molded parts. Other than dimensional accuracy and surface roughness, Nidagundi et al. BIB013 analyzed the impact of layer thickness, build orientation, and raster orientation on the ultimate tensile strength property. The number of experimental runs was selected by a Taguchi orthogonal array, and a low level of S/N ratio for all three parameters was recommended for tensile strength. Ziemian et al.  researched raster orientation as the only variable to determine the significance and the optimum level of the parameter for tensile properties. For this purpose, ABS parts were produced for different raster orientations, and tensile properties (yield strength and ultimate strength) were found to be maximum at 0 • raster orientation and minimum at 90 • raster orientation. Wittbrodt et al. BIB014 showed that the filament color of PLA was found to be significant for tensile properties. Torres et al. BIB015 investigated the influence of extrusion temperature, print speed, raster orientation, infill density, layer thickness, and perimeter (number of shells) on the tensile properties of PLA parts for different build orientations. Their outcome indicated that build orientation was one of the most significant parameters for tensile strength, and other tensile properties were also affected by build orientation. Torrado et al. BIB016 investigated the tensile strength of FDM parts for a set of unique variables, part geometry, and raster orientation. In their research, ABS parts were built for different geometries (Type I, IV, and V) of ASTM D638 standard, as well as different raster orientations. Rankouhi et al. BIB017 analyzed the importance of two process parameters (layer thickness and raster orientation) for the tensile properties of FDM built ABS parts. For experimental analysis, they considered two and three levels of layer thickness and raster orientation, respectively. According to their experimental results and statistical analysis, layer thickness and raster orientation, as well as their interaction, were significant. Additionally, the ultimate tensile strength and elastic modulus were maximum at lower levels of both parameters. The microscopic inspection of the fracture area showed that a smaller air-gap-to-material ratio contributed to tensile properties. Chacon et al. BIB018 investigated the importance of layer thickness, print speed, and build orientation for tensile properties. They showed that tensile strength was minimum at an upright build orientation (90 • ) and was almost the same at two other build orientations (on-edge and flat). Another finding was that the levels of layer thickness and print speed depended on build orientation. Uddin et al.  determined the impact of three process parameters on tensile properties. They showed that the mechanical properties of FDM parts, regardless of material, were lower than injection molded parts. The experimental outcomes revealed that the combination of process parameters was the same as the combination obtained by Chacon et al. BIB018 . Cantrell et al.  showed that tensile properties (yield strength and ultimate strength) were minimum at upright built orientation, and maximum at flat and on-edge build orientations for ABS and PC parts, respectively. Also, the authors showed that tensile properties were maximum at (0 • /90 • ) and (−45 • /45 • ) raster orientations for ABS and PC parts, respectively. Raney et al. BIB019 produced ABS parts using a Uprint SE 3D printer and analyzed the influence of build orientation on tensile strength. Aligned with most researchers, tensile strength was found to be maximum at on-edge build orientation. Qattawi et al. BIB020 determined significant parameters for tensile properties from build orientation, infill density, infill patterns, print speed, extrusion temperatures, and layer thickness. Among the six parameters, build orientation, layer thickness, infill density, and extrusion temperature were significant for tensile properties (Young's modulus, tensile strength, yield strength). Liu et al. BIB021 analyzed layer thickness, build orientation, raster orientation, raster width, and air gap and determined an optimum combination of process parameters for the tensile properties. The authors designed parts for the tensile test and the experiment according to GB/T 1040.2-2006 (Chinese Standard) and a Taguchi orthogonal array, respectively. From the five parameters, layer thickness (high), build orientation (60 • ), and raster orientation (−45 • /45 • ) were significant for tensile strength. The optimum levels of significant parameters were different from most of the existing research. Tontowi et al.  investigated layer thickness, build orientation, and raster orientation for tensile strength, as well as dimensional accuracy, and showed that build orientation was the most significant parameter. The authors also recommended that RSM was a better approach than a Taguchi orthogonal array. According to Mahmood et al.  , the ultimate tensile strength of ABS parts depended on the cross-section area (width × thickness), infill density, and number of shells. The property was proportional to infill density and number of shells; however, it was inversely proportional to the cross-section area. A metamodel for tensile force was developed by Raju et al. BIB023 , and they showed that layer thickness and build orientation were also the two most significant parameters among the four parameters for tensile properties. Aw et al. BIB024 determined the impacts of infill density and infill pattern (rectilinear and line) on the tensile properties of ABS/ZnO and conductive ABS/ZnO (CABS/ZnO) built parts. Their study revealed that 100% infill density and a line infill pattern maximized tensile strength. Similar to Mahmood et al.  , Kung et al.  showed that the cross-section area and the number of shells were significant for tensile strength. Additionally, Kung et al.  showed that tensile strength was maximum at a −45 • /45 • raster orientation. Vosynek et al.  compared PETG filaments produced by two different suppliers. They considered filament color, infill pattern, build orientation, infill density, and raster orientation as variables, showing that build orientation was the most significant parameter, and the tensile strength was maximum at a flat build orientation. Infill density and raster orientation were also significant for tensile strength. For FDM produced PEEK parts, Deng et al. BIB025 designed experiments according to a Taguchi orthogonal array, and showed that high print speed, low layer thickness, and high extrusion temperature were preferable for tensile strength. However, one of their contradictory outcomes was that the tensile strength was maximum at 40% infill density instead of at maximum infill density (60%). Rinanto et al. BIB026 applied the Taguchi orthogonal array for experimental design, and the controllable parameters were infill density, raster orientation, and extrusion temperature for PLA parts. The study revealed that a high extrusion temperature and infill density and a 45 • raster orientation were optimum for tensile strength. Fernandes et al.  analyzed infill density, extrusion temperature, raster orientation, and layer thickness, and the optimum combination for tensile properties was high infill density and extrusion temperature, low layer thickness, and 0 • /90 • raster orientation. On tensile strength, the influence of layer thickness, print speed, and infill density was separately analyzed by Taiyong et al. BIB022 . Tensile strength was maximum at low layer thickness and high infill density; however, unlike other research, it was shown that tensile strength was maximum at low print speed. Rodríguez-Panes et al. BIB027 compared the tensile properties of FDM built ABS parts and PLA parts by varying layer thickness, infill density, and build orientation. The tensile properties (modulus of elasticity, nominal strain at break, yield stress, and tensile strength) of PLA were better than the case of ABS. Short discussion and summary: Compared to any other part characteristics, tensile properties, especially tensile strength, are the most analyzed part characteristics in FDM printed parts. From existing research, the build orientation was found to be the most significant parameter, and tensile strength was maximum at 0 • (or flat/on-edge) build orientation. At this build orientation, the direction of filament fiber extrusion is parallel to the direction of the applied load. Layer thickness depends on other parameters, for instance, build orientation, and is optimum at 0 • build orientation. Low layer thickness is recommended for tensile properties. It is safe to conclude from the current research, as well as general knowledge, that tensile strength is maximum at high infill density and a high number of shells. At high density, interlayer bonds become strong. High extrusion temperature is preferable for tensile strength. This is because, at a high temperature, the fluidity of the filament increases, and interlayer bonds become stronger. The optimum raster orientation for tensile strength is still contradictory, but it may be concluded that a 0 • /90 • or −45 • /45 • raster orientation is optimum. Additionally, the color is also a significant factor for tensile strength, and tensile properties are maximum for natural color filaments.