A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Compressive Strength <s> In this study, the Taguchi method, a powerful tool to design optimization for quality, is used to find the optimal process parameters for fused deposition modeling (FDM) rapid prototyping machine that was used to produce acrylonitrile butadiene styrene (ABS) compliant prototype. An orthogonal array, main effect, the signal-to-noise (S/N) ratio, and analysis of variance (ANOVA) are employed to investigate the process parameters in order to achieve optimum elastic performance of a compliant ABS prototype so as to get maximum throwing distance from the prototype. Through this study, not only can the optimal process parameters for FDM process be obtained, but also the main process parameters that affect the performance of the prototype can be found. Experiments were carried out to confirm the effectiveness of this approach. From the results, it is found that FDM parameters, i.e. layer thickness, raster angle and air gap significantly affect the elastic performance of the compliant ABS prototype. The optimum levels of parameters at different angle of displacement are also presented. © 2005 Elsevier B.V. All rights reserved. <s> BIB001 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Compressive Strength <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> BIB002 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Compressive Strength <s> The ever-growing adoption of Additive Manufacturing (AM) can be attributed to lowering prices of entry-level extrusion-based 3D printers. It has enabled use of AM for prototypes and, often, to produce complex custom commercial products. With increasing access to material extrusion-based 3D printers and newer materials, the influence of print parameters, specifically infill patterns on the mechanical strength and print costs, needs to be investigated. This study presents the relationship between various infill designs and different mechanical properties based on ASTM testing standards along with production cost-time. Relevant infill designs are recommended based on loading conditions and savings in production cost when compared to solid infill design. The influence of production cost based on production grade and entry-level printers on selection of infill design is presented. Findings from this study will help formulate criteria for selection of optimal infill design based on loading conditions and cost of printing. <s> BIB003 </s> A Systematic Survey of FDM Process Parameter Optimization and Their Influence on Part Characteristics <s> Compressive Strength <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> BIB004
For the functional use of FDM printed parts, mechanical properties are also important, along with dimensional accuracy and surface roughness. Compressive strength is one of the most important mechanical properties and, like other part characteristics, it is also affected by process parameters. For the compressive test, almost all papers followed the ASTM 695 standard for compression test of rigid thermoplastics, as there is no standard for testing the mechanical properties of additive manufacturing build parts. In the FDM process, the generally used test specimens for this standard are shaped as follows: (1) right cylinder with 12.7 mm diameter and 25.4 mm height, or (2) rectangular prism with 25.4 mm × 12.7 mm × 12.7 mm dimensions. The speed of the load shell for the testing of compressive properties is in the range of 1.3 ± 0.3 mm/min. In this section, the surveyed literature related to compressive strength is systematically reviewed. Ang et al.  used the FDM process to produce an ABS scaffold structure for tissue engineering and analyzed the impact of different process parameters (air gap, raster width, build orientation, build layer, and build profile). Among those parameters, air gap and raster width were the two significant parameters for compressive strength, and the preferable levels for both parameters were lower and upper levels, respectively. Bagsik et al.  analyzed the impact of build orientation on the compressive properties of ULTEM™ 9085 built parts, and only two build directions were considered, 0 • and 90 • . Their experimental results showed that the compressive property was higher along 90 • . Sood et al. BIB002 investigated the influence of five process parameters on compressive stress, but also developed a quadratic equation that showed the relationship between process parameters and compressive stress. Their outcomes indicated that a complex nonlinear relation existed, and the interaction of process parameters was also important for compressive stress. Unlike the previous research, their results also showed that low build direction, along with high layer thickness, increased compressive stress, but raster width was insignificant. For a full factorial experiment, extrusion temperature, raster width, filament color, raster orientation, and air gap were considered as variables, and the impact of the variables on compressive strength was analyzed by Ahn et al.  . They recommended five build rules for producing a part by FDM based on an experimental study. Unlike most research findings, the experimental results of cylindrical-shaped ABS parts showed raster orientation was significant, but build orientation was insignificant for compressive strength. Lee et al. BIB001 analyzed only the influence of build orientation on compressive strength and showed that build orientation was significant, and the strength was maximum at 0 • . They concluded that parts produced by additive manufacturing had a low compressive strength compared to other processes, but FDM process produced parts had a relatively good compressive strength. Wu et al.  showed that layer thickness was significant for compressive strength, but their outcomes indicated that the center level maximized the properties. In order to compare ABS and PEEK materials, they produced parts by both materials and tested the compressive strength and modulus. The outcome was that PEEK had higher mechanical properties, although it demonstrated an inconsistent stress-strain curve when compared to ABS. Compressive properties of ABS parts were analyzed by Baich et al. BIB003 , and the infill pattern was their chosen variable. The summary of their work was that the compressive properties of a part increase as shape complexity increases. Hernandez et al.  analyzed the importance of build orientation for maximizing compressive properties, along with other mechanical properties. For this, three levels of the process parameters were considered, and parts were produced by a uPrint SE Plus 3D printer from ABS P430 filaments. The experimental outcome was that 0 • build orientation increased compressive strength, compressive yield strength, and compressive modulus. On the other hand, compressive strength was found to be minimum at 45 • build orientation. Unlike other researchers, Zaman et al. BIB004 produced function parts for the aerospace industry to study how layer thickness, infill pattern, infill density, and number of shells were important for compressive properties. In the paper, the experimental study was designed according to a Taguchi orthogonal array (L8), and specimens were produced from PLA and PETG by a Makerbot Replicator 2X and Open Edge HDE machine, respectively. The outcome of the experiment and statistical analysis (ANOVA and S/N ratio) showed that the compressive strength of PETG built parts was slightly better than PLA built parts. Note that, in their study, different machines were used for different materials.