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Design+ Analysis of 3D-printed anisotropic cells

simplified model displaying an average Young’s modulus define and optimize process parameters while maintaining
approximately 1 GPa higher than the detailed model; alignment with engineering specifications. A notable
despite this discrepancy, the difference remains minimal. advantage of this method is that designers, engineering
The deformation and maximum internal stress of the designers, and product designers do not need to have
detailed model were found to be higher than those of the in-depth knowledge of the manufacturing process.
simplified model under the same load conditions. 4. Conclusion
Despite minor differences between the models, their
equivalence can be demonstrated, with the simplified In summary, this research demonstrated the anisotropic
model offering a significant reduction in computational behavior of FFF specimens through both computational
time – from about 1 h for the detailed model to just 15 s. In simulations and experimental tests, successfully validating
addition, this study examined the use of linear orthotropic numerical models against experimental data. The study
stiffness cells based on 3D printing process parameters identified key and secondary factors influencing anisotropic
through both experimental and theoretical approaches. cell behavior, including layer height, filament diameter,
hexagonal infill diameter, air gap, and line overlap.
As a result, a simplified model was developed, and
comparisons among the detailed, simplified, and experimental It was observed that raster cells exhibit greater resistance
models showed a strong correlation between them. This compared to hexagonal and grid cells, primarily due to
advancement enables the design of complex objects with the lower density of hexagonal and grid cells. However,
various anisotropic internal structures and the identification hexagonal cells were found to have a higher average Young’s
of process parameters corresponding to these cell properties. modulus compared to grid and raster cells. Variables such
This leads to more reliable design specifications compared to as layer height (for raster cells), hexagon diameter (for
current techniques, ensuring an accurate representation of hexagonal cells), and air gap (for grid cells) were identified
the mechanical behavior of 3D-printed objects. as having significant effects on equivalent break stress and
Thus, the simplified model can be used for designing elasticity modulus. In addition, the combination of bead
such objects, reducing computational costs across width and layer height suggests that larger beads produced
various environments, including computer-aided design, stronger objects compared to smaller bead filaments.
computer-aided engineering, slicers, and computer-aided The study determined the coefficients for linear
manufacturing. orthotropic compliance matrices, leading to a simplified
The basic design specifications can be divided into two numerical model with low computational costs. This
categories: process-based and engineering-based. research represents an initial framework for integrating

As illustrated in Figure 11A, the number of parameters anisotropy characteristics into design specifications
and the degree of anisotropic strategies can be effectively despite manufacturing variations like infill density and
specified for objects with simple material behavior. layer height.
However, objects requiring more complex levels of Two design specification methods were proposed to
anisotropy may lead to specifications that are harder to standardize the mechanical behavior of both complex and
interpret and visualize. simple 3D-printed objects. Nonetheless, many challenges
This approach integrates the process directly into remain, and further research is needed to refine the
the design, ensuring that the final product aligns with integration of anisotropy in design specification based on
desired outcomes. Consequently, defining process process parameters.
parameters becomes an integral part of design activities.
This underscores the importance of product engineers, Acknowledgments
designers, and engineering designers having a thorough The authors would like to thank the University of São
understanding of the manufacturing process to achieve Paulo and Zirclab Medical Devices for their support and
optimal results. infrastructure.
Another sort of specification is based on engineering
parameters, where the basic orthotropic coefficients define Funding
the material grades, as presented in Figure 11B. In this case, This research was partially funded by the Brazilian National
the process parameters are defined during manufacturing Council for Scientific and Technological Development
planning using a reference table. (CNPQ) under the National Project Grant (Grant no.:
This approach empowers manufacturing engineers to 350377/2022 – 7).

Volume 2 Issue 1 (2025) 12 doi: 10.36922/dp.3779