FDM (fused deposition modeling) is one of the most commonly used technologies in additive manufacturing. This technology is used to additively manufacture components from various polymer materials, mostly PLA (polylactic acid), etc. PLA filament is a widely used polymer for 3D printing due to its biodegradability, biocompatibility, and processability. In the study, PLA raw material and cellular auxetic structures were used in the design. Auxetic designs are called metamaterials, they are structures with advanced properties and can be obtained with various geometries. The auxetic designs used in the study are missing rib, re-entrant honeycomb and chiral. One of the biggest advantages of auxetic cellular materials is that it is not bulk material. Having a skeletal structure provides high strength at low density. Today, based on this mechanism, designs that can be used in engineering applications are being studied. It has an important place especially in the medical field, as well as in the areas where high precision and specific products are designed and produced. Considering its relationship with 3D printing technology, 3D printing enables the fabrication of auxetic structures for complex and personal designs. The novelty of auxetic structures comes from their topological features, which display counterintuitive response to the applied load. For the purpose of compare the properties of mechanical tensile, compression, surface roughness tests were applied. It is concluded that the presence of chiral structures improves mechanical performance. The chiral auxetic sample exhibited a maximum stress of 6.68 MPa, the missing-rib auxetic sample displayed a maximum stress of 2.26 MPa, and the re-entrant auxetic sample demonstrated a maximum stress of 3.68 MPa. These results obtained from the tests align well with the range reported in the literature, which falls between 1-12 MPa. The surface roughness of the all-auxtetic structure, perpendicular to the printing direction was higher than the measurements taken parallel to the printing direction.

Supplementary tools are needed to perform the engineering process in additive manufacturing. Simufact Additive is a simulation tool of MSC Software that provides a solution for structural behavior during this process. Simufact Engineering and MSC Software have released a software solution to predict the most critical failure in metal AM (Additive Manufacturing) – part distortion. Analyzing provides a solution for industrial process engineers to shorten their process development time and produce high quality parts with this novel manufacturing methodology, reaching analyzing provides printing parts “right the first time”. Metal powder bed fusion manufacturing faces many challenges. The main issue is occurs distortions and high residual stresses. The aim of the study analysis of effects on voxel-based surface mesh applications on bracket part used in aviation. In this study, the voxel mesh element size increases, the amount of distortion calculated on the part decreases. Increasing the element size value will reduce the working time.

This research is purposed to analyze the bending strength and surface roughness results of polylactic acid samples produced by fused filament fabrication. Using the experimental design method, the effect of fill density, layer thickness, infill, and raster orientation parameters on the bending and surface roughness performance of samples was investigated. In the study, the individual effects and interactions of the main four factors were analyzed using 2³3¹ mixed-level factorial design approaches. Whereas linear and honeycomb filled were preferred in the experimental design, 30°, 60°, and 90° angles were used as raster orientation and 50 % and 100 % were used as fill density. In addition, 0.15 mm and 0.05 mm were printed as layer thicknesses. Samples were tested using a stylus profilometer (Mitutoyo SJ-301) to determine surface roughness characteristics, and the AUTOGRAPH AG-IS 100 KN was utilized to analyze the bending strength of the parts. In addition, fracture surfaces were analyzed by stereo microscope at various magnifications. The data were analyzed using the Minitab 19 software program. The most effective parameter for bending strength is the layer thickness with 40.02 %. In addition, it has been observed that the fast honeycomb fill pattern has higher strength than the linear fill pattern. Inversely to literature, according to our result, when the layer thickness is reduced, the surface roughness increases, because of the bubble on the surface of the printed sample. The results obtained from this study will provide preliminary information to the users in order to produce the parts that will provide the necessary requirements according to the usage area with minimum time and costs.

Thanks to the developing technology and softwares, analysis and optimization of the engineering parts can be done through computer programs nowadays. Softwares play an active role not only in analysis but also in reducing the material cost as a result of lightening the part with changes in design. Manufacturing methods and comparisons of these methods with each other have always been the subject of research. Choosing the methods of manufacturing of material has a great importance for enterprise. The loads and strength of the designed part under operating conditions are very important for the manufacturer. The pros and cons of both production methods which are additive manufacturing and machining have been investigated and these methods have been compared for the use of Pet-G material. An FDM (Fused Deposition Modeling) type 3D (three-dimensional) printer has been used in the additive manufacturing method and CNC Router (Computer Numerical Control Router) has been used for the machining method. A part design created in accordance with the mentioned manufacturing methods and its mechanical properties after its twice optimization have been examined and compared. After the optimizations, the targeted reduction on the mass of production has been achieved. After the optimization process, the sample has reduced by about 63% in volume and mass according to the design program. The mass of the sample, which is approximately 300 grams, has been reduced to 100 grams. As a result of the tests, it has been observed that the strength values of the samples manufactured by machining are higher.