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Fused Deposition Modeling (FDM) is one of the most widely explored additive manufacturing methods that uses thermoplastic materials to manufacture products. Mechanical properties of parts manufactured using FDM are influenced by different process parameters involved during manufacturing as they impact the bonding among different layers of the cross...
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... average Young's modulus of the five samples of each infill pattern with each print orientation is considered to be the representative of that pattern and orientation. Summary of mechanical properties of each infill pattern with each orientation is shown in table 2. Figure 25 shows the maximum flexural strength of the specimens. We observe that cubic infill pattern with edgewise orientation has the highest maximum flexural stress of 107.95 MPa, closely followed by concentric pattern with flatwise orientation and cubic pattern with flatwise orientation. ...
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... Upright print orientation, tetrahedral infill pattern has the highest maximum flexural stress (closely followed by lines infill pattern) and triangles infill pattern has the lowest maximum flexural stress. Figure 26 shows boxplot of different infill patterns with maximum infill pattern regardless of print orientations. We can clearly see that cubic patterns tend to have higher maximum flexural strength compared to other infill patterns. ...
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... patterns tend to have lower maximum flexural strength compared to other infill patterns. From figure 27, we observe that median value of maximum flexural stress in flatwise orientation is higher than rest of the two orientations. In general, flatwise orientations tend to have higher maximum flexural stress. ...
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... print orientation tend to have much lower maximum flexural stress compared to the other two types. Figure 28 shows the flexural modulus obtained for different infill patterns and orientations. We observe that triangles infill pattern with flatwise orientation has the highest flexural modulus of 3.36 GPa and zigzag infill pattern with edgewise orientation has the lowest flexural modulus of 2.185 GPa. ...
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... upright orientation, cubic infill pattern has the highest flexural modulus (closely followed by triangles infill pattern) and zigzag infill pattern has the lowest flexural modulus. Figure 29 shows boxplot of flexural modulus for all the infill patterns regardless of print orientation. We observe that cubic infill pattern tends to have higher flexural modulus compared to other patterns and zigzag pattern tends to have lower flexural modulus compared to other infill patterns. ...
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... upright orientation, tetrahedra pattern has the highest and triangles pattern has the lowest maximum flexural strain. figure 32, we observe that lines infill pattern tends to have higher and triangles infill pattern tends to have lower maximum flexural strain. Applications where ductile property is desired lines pattern is a plausibly better choice over the other patterns considered in this study. ...
Citations
... There are numerous parameters which can effect on mechanical characteristics of 3D-printed products such as: printing direction [2,3], layer thickness [4,5], infill geometry [6][7][8], built orientation [7,9], print morphology [4,10], printing speed [11,12], extrusion temperature [11], raster angle [5,[12][13][14][15][16][17], moisture content [13], extruder nozzle diameter [18,19], and thermal treatment [20]. Hsueh et al. [21] studied the influence of printing temperatures and speeds on the PLA and PETG materials of FDM under mechanical and thermal loading. ...
... There are numerous parameters which can effect on mechanical characteristics of 3D-printed products such as: printing direction [2,3], layer thickness [4,5], infill geometry [6][7][8], built orientation [7,9], print morphology [4,10], printing speed [11,12], extrusion temperature [11], raster angle [5,[12][13][14][15][16][17], moisture content [13], extruder nozzle diameter [18,19], and thermal treatment [20]. Hsueh et al. [21] studied the influence of printing temperatures and speeds on the PLA and PETG materials of FDM under mechanical and thermal loading. ...
The growing application of 3D printing demands the attention of designers regarding the damage mechanism in the products of such kind of additive manufacturing procedure. However, limited detailed studies were available in the related literature. The main contribution of the current work is to explore the failure mechanism of 3D-printed parts via optical tools, such as Scanning Electron Microscopy (SEM) images on a micro-scale and Digital Image Correlation (DIC) images on a macro-scale. Mechanical characterization, e.g., tensile, compression, and torsional properties of 3D-printed specimens were carried out in experimental tests to measure the basic constants in the raster and its perpendicular directions. Also, the fractographic method was utilized to qualitatively analyze the damage initiation and propagation under different loading conditions. The remarkable findings of the current study have pointed out that the 3D-printed products demonstrated orthotropic behavior in various types of experiments. As a result, the average tensile strength, Young modulus, and elongation at breakage measured in filament direction were 38%, 11%, and 47% higher than those in transverse direction. The SEM images of the damaged specimen show that the tensile failure in specimens loaded in filamentary direction was occurred in two-step softening stages. It was affected by the filaments cross-sectional expansion. In torsional specimens, the different damage modes were observed owing to the bond failure of the adjacent filaments as a 3D printing procedure. The results of the compressive specimens subjected to the compressive load in a raster filaments’ direction indicate the micro-buckling and kinking whereas when the load applies transversely, there is filament debonding phenomenon accompanied by densification and plasticity were observed.
... Camargo et al. [24] found that the flexural strength increased as the infill density increased. In a recent study on the effect of infill patterns on flexural strength, Rajukumar [37] discovered that cubic infill patterns tend to exhibit the highest maximum flexural strength, followed by concentric infill patterns, and zigzag infill patterns tend to have the lowest maximum flexural strength. This research analyzed and compared six distinct infill patterns. ...
The mechanical properties of fused deposition modelling (FDM) parts are the most common indicator in defining their potential for a specific application. The reason for the low strength of FDM printed parts is that they are not as strong as their conventionally manufactured counterparts. It is an anisotropic characteristic due to the voids between the deposition lines and the low strength of the thermoplastic material. This paper reviews the factors influencing the mechanical properties of FDM parts from various aspects, including the development of new materials such as FDM filament, process parameter optimization, process parameter adjustment, and other methods for achieving better mechanical properties of FDM parts. The results pointed out that the FDM applications are limited by the material available for filament feedstock and the nature of the FDM process that introduces voids between lines. In addition, the review showed that most research conducted on FDM parameters is about the cause-and-effect relationship but lacks research to relate this effect to the microstructure and mesostructure of FDM parts as well as the mechanism that controls the bonding strength of the part.
Additive manufacturing, also known as 3D printing, is transforming the industry and becoming more common every day due to its considerable time saving and lower costs, compared to the established conventional manufacturing methods. The mechanical strength of 3D printed products is affected by the parameters of the 3D printing process. Thermoplastic Polyurethane (TPU) is a type of elastomer, capable of being used on any fused deposition modelling (FDM) 3D printer. A series of TPU test pieces with different infill density and patterns were produced using a FDM printer. The influence of infill parameters on the 3D part’s mechanical properties has been evaluated. Five patterns with a range of infill densities were compared in this study. The tensile properties of the printed specimens were influenced by the infill density, whereas the infill pattern used in this study has marginal effects. The grid pattern with 100% infill density showed the highest tensile strength, with a value of 4.43 MPa. The results were compared with specimens, which were prepared through conventional compression moulding. The dynamic mechanical thermal analysis (DMTA) and load–deflection analysis (LDA) tests showed that specimens with 100% infill density may not be significantly affected by different infill patterns selected in this study under low strain testing conditions.
