A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB001 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> This paper describes an experimental design technique for determining the optimum surface finish and dimensional accuracy of a part built by the Fused Deposition Modeling (FDM) process. The design investigates the effect of the process parameters layer thickness, road width, raster angle and air gap on the surface finish and dimensional accuracy. Experiments were conducted using Taguchi's design of experiments with three levels for each factor. The results are statistically analyzed to determine the significant factors and their interactions. From the ANOVA analysis, it was found that the layer thickness and road width affect the surface quality and part accuracy greatly. Raster angle has little effect. But air gap has more effect on dimensional accuracy and little effect on surface quality. <s> BIB002 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB003 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> Design of experiments (DOE) is a methodology based on statistics and other disciplines for arriving at an efficient and effective planning of experiments with a view to obtain valid conclusions from the analysis of experimental data. Design of Experiments determines the pattern of observations to be made with a minimum of experimental efforts. DOE process is implemented to FDM process to optimize the processing time. In this study three process parameters at three levels are selected. Using full factorial design totally 27 experiments are required. Using design of experiments and orthogonal array the total number of experiments are reduced to 9. Therefore the optimum processing time will be obtained in these 9 experiments. Thus 9 experiments are conducted and the experimental data obtained from the experimental trails are analyzed using S/N ratio and ANOVA analysis. <s> BIB004 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> Abstract Fused deposition modelling (FDM) is gaining distinct advantage in manufacturing industries because of its ability to manufacture parts with complex shapes without any tooling requirement and human interface. The properties of FDM built parts exhibit high dependence on process parameters and can be improved by setting parameters at suitable levels. Anisotropic and brittle nature of build part makes it important to study the effect of process parameters to the resistance to compressive loading for enhancing service life of functional parts. Hence, the present work focuses on extensive study to understand the effect of five important parameters such as layer thickness, part build orientation, raster angle, raster width and air gap on the compressive stress of test specimen. The study not only provides insight into complex dependency of compressive stress on process parameters but also develops a statistically validated predictive equation. The equation is used to find optimal parameter setting through quantum-behaved particle swarm optimization (QPSO). As FDM process is a highly complex one and process parameters influence the responses in a non linear manner, compressive stress is predicted using artificial neural network (ANN) and is compared with predictive equation. <s> BIB005 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB006 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB007 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB008 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB009 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> Fused deposition modeling (FDM) is one of the most popular additive manufacturing technologies for various engineering applications. FDM process has been introduced commercially in early 1990s by Stratasys Inc., USA. The quality of FDM processed parts mainly depends on careful selection of process variables. Thus, identification of the FDM process parameters that significantly affect the quality of FDM processed parts is important. In recent years, researchers have explored a number of ways to improve the mechanical properties and part quality using various experimental design techniques and concepts. This article aims to review the research carried out so far in determining and optimizing the process parameters of the FDM process. Several statistical designs of experiments and optimization techniques used for the determination of optimum process parameters have been examined. The trends for future FDM research in this area are described. <s> BIB010 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> Abstract The performance of rapid prototyping (RP) processes is often measured in terms of build time, product quality, dimensional accuracy, cost of production, mechanical and tribological properties of the models and energy consumed in the process. The success of any RP process in terms of these performance measures entails selection of the optimum combination of the influential process parameters. Thus, in this work the single-objective and multi-objective optimization problems of a widely used RP process, namely, fused deposition modeling (FDM), are formulated, and the same are solved using the teaching-learning-based optimization (TLBO) algorithm and non-dominated Sorting TLBO (NSTLBO) algorithm, respectively. The results of the TLBO algorithm are compared with those obtained using genetic algorithm (GA), and quantum behaved particle swarm optimization (QPSO) algorithm. The TLBO algorithm showed better performance as compared to GA and QPSO algorithms. The NSTLBO algorithm proposed to solve the multi-objective optimization problems of the FDM process in this work is a posteriori version of the TLBO algorithm. The NSTLBO algorithm is incorporated with non-dominated sorting concept and crowding distance assignment mechanism to obtain a dense set of Pareto optimal solutions in a single simulation run. The results of the NSTLBO algorithm are compared with those obtained using non-dominated sorting genetic algorithm (NSGA-II) and the desirability function approach. The Pareto-optimal set of solutions for each problem is obtained and reported. These Pareto-optimal set of solutions will help the decision maker in volatile scenarios and are useful for the FDM process. <s> BIB011 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB012 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <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> BIB013 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> Abstract Designing and manufacturing functional parts for fields such as engineering and medicine is a major goal of Fused Deposition Modeling (FDM). These activities should be supported by knowledge on how different settings of process parameters impact the mechanical behavior of the products. However, obtaining this information is a quite complex task given the large variety of possible combinations of materials-3D printers-slicing software-process parameters. Thus, the importance of reviewing the current research on this topic for identifying practical and useful aspects, key process parameters and limitations, but also for understanding to what extent the results of these researches are relevant and can be applied in further studies and real applications. A systematic literature search was performed based on classification according to the type of 3D printing polymer. The most significant process parameters considered as influencing FDM specimens' tensile, compression, flexural or impact strengths are discussed considering the results presented in the literature. A necessary distinction between the mechanical properties of material and testing specimens (as given by producers and by experiments) and the mechanical behavior of a FDM end-part is also made. <s> BIB014 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Introduction <s> The control of process parameters to customize a part has been a value-added ability related to additive manufacturing (AM). In this paper, parametric optimization of fused deposition modeling (FDM) process is performed using Taguchi design of experiments (DOE). Two sets of experiments were conducted on an industrial case study from the aerospace industry to assess the impact of FDM process parameters: layer thickness, shells, infill pattern, and infill percentage, on the compressive strength of the case study. A generic methodology was also proposed. Analysis of variance (ANOVA) and signal-to-noise (S/N) ratio analysis were performed to evaluate the importance of experimental error, finding the optimal combination of process parameters for maximizing the compressive strength, and assessing the robustness of the design. The paper concluded with the display of results, discussion, and conclusions drawn. <s> BIB015
Currently, fused deposition modeling (FDM) is not only used to produce visual aids, conceptual models, and prototypes, but it is also used to produce functional parts such as drilling grids in the aerospace industry BIB015 and edentulous mandible trays  . It reduces assembly cost as it is capable of manufacturing complex geometry and flexible function parts from a stereolithography (STL) file by depositing two-dimensional (2D) layers on a build platform. As of the time of writing, researchers are still working on developing new materials, as well as improving existing materials used in FDM parts in different fields such as aerospace, biomedical, and many other fields. However, the application of the FDM process in manufacturing functional parts is limited due to different drawbacks such as irregular surface, poor mechanical properties, and low accuracy. Although low accuracy is a relative term, as some applications do not require high accuracy (prototypes or display parts), in order for FDM to be more acceptable in the industry and for it to be a good candidate to mass-produce printed parts, accuracy is a basic requirement that is sought for. To produce good functional parts and increase the market share of FDM parts, it is necessary to produce parts with stable qualities to meet specific requirements. The FDM process has several parameters that have a significant impact on built parts. All these parameters affect the bonding between and within the deposited layers. A part with desired qualities can be produced by selecting an optimum combination of process parameters. An important role is also played by the use of the best thermoplastic polymer for the proposed use of the part. A huge number of researchers analyzed various controllable parameters to achieve desirable properties of parts BIB008 BIB006 BIB012 BIB002 BIB009 , and many also worked on optimizing process parameters BIB005 BIB004 . Many of the researches optimized process parameters in order to improve a single part's quality. Rayegani and Onwubolu worked on optimizing tensile strength with a differential evolution (DE) approach BIB007 . Some researchers also considered more than one part's quality, but they were analyzed separately BIB013 BIB003 BIB001 . Additionally, a more advanced approach is to consider two or more parts' qualities and optimize them simultaneously to obtain a set of optimum combination(s) of parameters. Akande  , Gurrala et al.  and Rao et al. BIB011 worked on multi-objective optimization. In addition to this review paper, interested readers are encouraged to review two published review papers on FDM process parameter optimization. The first manuscript is by Mohamed et al. BIB010 , where research works until the year 2014 were analyzed. The second manuscript is by Popescu et al. BIB014 ; they reviewed research that considered only mechanical properties as the part characteristics. To complement the two reviewed papers, this paper aims to fill the gaps by systematically representing current and future research trends carried out by researchers on FDM process parameter optimization and their influence. Based on the authors' knowledge, at the time of writing, the optimization information for FDM process parameters was not concisely reviewed. This paper also serves as an aid for current and future researchers, practitioners, and the general public to set up experiments for the FDM process and to do research on improving or optimizing the characteristics of FDM parts. The rest of this paper is organized as follows: Section 2 describes process parameters, equipment, and materials. Section 3 reviews the existing papers on FDM part characteristics. In Section 4, the current works on numerical process parameter optimization for the FDM process are discussed. Section 5 defines challenges, opportunities, and future research areas in the improvement of FDM part characteristics. Section 6 provides conclusions.