A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB001 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB002 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB003 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB004 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural Strength <s> As the ability to resist deformation under load, flexural strength is an important property of every material. Fused Deposition Modeling (FDM) technology allows users to control the density of models through parameter which is termed air gap or infill. Since lower infill values significantly increase the building speed, test specimens were used with infill between 10 and 30%. Therefore, this paper discusses experimental analysis of the influence of layer thickness, deposition angle and infill on the maximum flexural force in FDM specimens made of polylactic acid (PLA). A 2 3 factorial experiment without replication was used with three center points. The results indicate a dominant, statistically significant influence of extrusion speed, significant interaction between deposition angle and infill, as well as the nonlinearity of effects. <s> BIB005 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural Strength <s> Abstract Fused deposition modeling (FDM) is one of the rapid prototyping methods that produce prototypes from plastic materials such as acrylonitrile butadiene styrene (ABS) by laying tracks of semi-molten plastic filament onto a platform in a layer wise manner from bottom to top. In FDM, one of the critical factor is to select the build up orientation of the model since it affects the different areas of the model like main material, support material, built up time, total cost per part and most important the mechanical properties of the part. In view of this, objective of the present study was to investigate the effect of the built-up orientation on the mechanical properties and total cost of the FDM parts. Experiments were carried out on STRATASYS FDM type rapid prototyping machine coupled with CATALYST software and ABS as main material. Tensile and Flexural specimens were prepared as per the ASTM standard with different built-up orientation and in three geometrical axes. It can be concluded from the experimental analysis that built orientation has significant affect on the tensile, flexural and total cost of the FDM parts. These conclusions will help the design engineers to decide on proper build orientation, so that FDM parts can be fabricated with good mechanical properties at minimum manufacturing cost. <s> BIB006 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural Strength <s> Additive Manufacturing (AM) technologies have been emerged as a fabrication method to obtain engineering components within a short span of time. Desktop 3D printing, also referred as additive layer manufacturing technology is one of the powerful method of rapid prototyping (RP) technique that fabricates three dimensional engineering components. In this method, 3D digital CAD data is converted directly to a product. In the present investigation, ABS + hydrous magnesium silicate composite was considered as the starting material. Mechanical properties of ABS + hydrous magnesium silicate composite material were evaluated. ASTM D638 and ASTM D760 standards were followed for carrying out tensile and flexural tests, respectively. Samples with different layer thickness and printing speed were prepared. Based on the experimental results, it is suggested that low printing speed, and low layer thickness has resulted maximum tensile and flexural strength, as compared to all the other process parameters samples. <s> BIB007 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB008 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB009 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Flexural 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> BIB010
Flexural strength is an important mechanical property like tensile and compressive strength for functional parts. ASTM D790 is an international standard for testing the flexural properties of thermoplastics. A three-point loading system is typically used for flexural strength. The load is applied to the specimen, and the specimen simply acts as a supported beam. In this section, the existing research on determining the impacts of FDM process parameters on flexural properties is summarized extensively. The impact of layer thickness, build orientation, raster width, raster orientation, and air gap on flexural strength was investigated by Panda et al. BIB001 , along with tensile strength. The outcome of their experimental study and statistical analysis was that all parameters, as well as their combination, were significant for flexural strength. Sood et al. BIB002 considered the same parameters, and a response surface equation for flexural strength was developed that showed the relationship between process parameters and the obtained strength. Other than that, response surface plots were also used to describe the significance of the interactions of two parameters for flexural strength. A high level of layer thickness and raster width, and a low level of the other parameters were deemed to increased flexural strength. The optimum raster orientation for flexural strength was determined by Fatimatuzahraa et al. BIB003 with ABS parts produced by a Dimension SST 768 FDM machine with four different of raster orientations. They concluded that flexural strength was maximum at a 45 • /−45 • raster orientation. Durgun et al. BIB004 investigated build orientation and raster orientation to determine the levels of both parameters that maximized the flexural strength of ABS parts. Their finding was that 0 • raster orientation and 0 • build orientation maximized flexural strength, as well as surface roughness. Lužanin et al. BIB005 produced PLA parts by a MakerBot Replicator 2 for investigating flexural strength. The analyzed process parameters were layer thickness, build orientation, and infill density. Based on the experimental results and statistical analysis (ANOVA), layer thickness and the interaction between build orientation and infill density were significant for flexural strength. Raut et al. BIB006 analyzed the impact of built orientation on flexural strength of ABS parts produced by a Stratasys FDM machine. For the build orientation, the outcome of the analysis was the same as the outcome by Durgun et al. BIB004 . Hernandez et al.  considered only one process parameter, which was build orientation, to analyze the impact on the flexural strength. Parts were produced according to ASTM D790 from ABS P430 filament, and the results indicated that flexural properties, like compressive properties, were maximum at 0 • build orientation. Liu et al. BIB008 designed their experiments based on a Taguchi orthogonal array, and PLA parts were designed according to GB/T 9341 (a Chinese testing standard). According to ANOVA analysis at a 5% significance level, they concluded that build orientation, layer thickness, and raster orientation were significant for flexural strength. Wu et al.  compared flexural properties along with tensile and compressive properties for PEEK and ABS. Unlike tensile and compressive properties, the experimental outcome showed that flexural properties were almost similar for both materials. Christiyan et al. BIB007 analyzed the impact of layer thickness and print speed on flexural strength. Unlike most research findings, the composite parts were built from ABS and hydrous magnesium silicate according to ASTM D790. The experimental investigation showed that flexural strength was maximum at a low layer thickness and print speed. The influence of two quantitative parameters (layer thickness and print speed) and one categorical variable (build orientation; flat, on-edge, and upright) on flexural strength was analyzed by Chacon et al. BIB009 . For flexural strength, like tensile strength, they developed a quadratic model for each build orientation. The flexural strength was found to be maximum at on-edge build orientation, and optimum layer thickness and print speed depended on build orientation. Raju et al. BIB010 considered layer thickness, build orientation, the support material, and the model interior as variables, and ABS parts were produced according to a Taguchi orthogonal array (L18). To demonstrate the relationship between the four process parameters and flexural strength, a linear regression model was developed, and, based on the equation, their research summary was that a high layer thickness and a low build orientation increased the flexural strength. Short discussion and summary: Flexural strength is one of the least analyzed mechanical properties in comparison to compressive and tensile strength. Based on the analysis of the existing research, it can be concluded that the relationship between flexural strength and process parameters is more complex compared to tensile or compressive strength. This is because, during flexural strength testing, a component experiences both tensile and compressive force. Flexural strength is maximum at 0 • build orientation. In this build orientation, the orientation of the filament is perpendicular to the direction of the load applied. Further research is required to know the impact of various process parameters, including layer thickness, raster orientation, print speed, and air gap on flexural strength. Based on the current literature review, the impact of some parameters such as infill pattern, extrusion temperature, and infill density on flexural properties was not widely analyzed. As one of the future research directions, it will be valuable for public information if more parameters are analyzed simultaneously to know the cumulative impact of printed parts on flexural strength.