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Materials Science in Additive Manufacturing Impact of cell angle on AlSi10Mg structures

identical impact loads, single-unit cells with different
design structures exhibited varying stress-strain responses
(Figure 14). According to Figure 12, under higher impact
loads, the structures undergo deformation, leading to
eventual failure. Specifically, the simulations demonstrate
that different structures and identical single-unit cells
with varying rotation angles exhibit distinct capacities for
withstanding the same impact load. This confirms that the
impact properties of the designed structure are influenced
by its rotation angles.
In the Octa series of structures, high-stress
concentrations occur at the junctions of the connecting
rods (highlighted by red circles in Figure 14) under impact
loading. The Octa-A structure, characterized by a greater
number of connecting rods and smaller inclination angles,
demonstrates enhanced load-bearing capacity compared to
the Octa-B structure. When the horizontal connecting rod
Figure 13. Comparison of energy absorption after two consecutive in Octa-A fails, the components with smaller inclination
impacts at a high energy level of 248 J for various porous materials with angles continue to support some load, allowing for partial
80% porosity
Abbreviations: Dodeca: Dodecahedral; Octa: Octahedral recovery of structural integrity. In contrast, Octa-B, which
is more affected by the horizontal connecting rod at the
it is noteworthy that Octa-A P80 exhibited a significantly upper end, transfers the load to the inclined components on
higher yield load, resulting in greater energy absorption both sides. This load transfer leads to fracture and eventual
capacity. This suggests that the Octa-A structure may collapse of the entire structure. Consequently, when the
possess inherent geometric advantages that promote early strain reaches ~51%, the Octa-A structure retains some
load redistribution, contributing to enhanced energy load-bearing capacity, whereas Octa-B exhibits greater
dissipation. In addition, after reaching a deformation of fracture failure and reduced load-bearing capability.
8.6 mm, Octa-A P80 displayed larger oscillations in load, In the Dodeca series of structures, large stresses are
indicating ongoing resistance within the structure. This generated at the intersections of the connecting rods at
behavior contrasts with Octa-B P80, suggesting a rapid loss the onset of impact loading (highlighted by red circles in
of structural resistance. Even after transitioning to the post- Figure 14), similar to the Octa structures. However, the
dense stage, the energy absorption capacity of the Octa-A subsequent deformation manifests distinct stress levels
P80 structure remained superior to that of the Octa-B P80 due to differences in unit cell design. Both Dodeca-A
(Figure 13). These findings highlight the critical role of and Dodeca-B lack connecting rods with sufficient load-
unit cell orientation in optimizing the energy absorption carrying capacity, resulting in suboptimal deformation
characteristics of porous structures subjected to higher- performance. The absence of adequately angled or
impact energies. positioned connecting rods compromises their ability to
redistribute stress effectively, leading to a substantial loss
3.3. Numerical simulation analysis of impact of resistance following the initial fracture. In contrast, the
behavior
Dodeca-C structure features a greater number of connecting
The mechanical test results confirm that the orientation rods with smaller angles relative to the initial direction of
angles of single-unit cells significantly influence the the load, enabling it to sustain impact loads more effectively
impact resistance and energy absorption capabilities of the during deformation. Even when some connecting rods fail,
designed LPBF-built AlSi10Mg Dodeca and Octa porous the remaining components continue to function (Figure 14,
structures. We further conducted numerical simulations vertical rods in Dodeca-C), providing resistance to impact
to analyze load-bearing characteristics from a single-unit deformation. Therefore, Dodeca-C exhibits higher impact
cell geometrical perspective to deepen our understanding resistance than the other structures in the Dodeca series,
of the different impact behaviors exhibited by various confirming that careful design consideration of rod
structures with distinct single-unit cell orientations. As placement and orientation can yield significant benefits
shown in Figure 14, the stress-strain behavior of these in structural performance. Furthermore, the numerical
structures, derived from rotating single-unit cells, was simulation approach provides a valuable tool for predicting
investigated through numerical simulations. Under and understanding the performance of porous structures

Volume 4 Issue 2 (2025) 13 doi: 10.36922/MSAM025130019