ScholarWorks@경상국립대학교

초록

Porous structures offer lightweight design and geometric flexibility for applications in transportation and bioengineering. Additive manufacturing, particularly laser powder bed fusion (LPBF), enables the fabrication of complex porous architectures. However, achieving an optimal balance between weight reduction and mechanical performance remains challenging.Therefore, further investigation into the design of porous structures is essential. This study explores the dynamic mechanical behavior of porous AlSi10Mg structures designed using a parametric modeling approach and the Voronoi tessellation algorithm. The structures, fabricated via LPBF, feature varying single-unit cell rotation angles and porosities. The dynamic mechanical behaviors were experimentally investigated under different impact energies to assess the influence of single-unit cell rotation on impact properties, complemented by finite element analysis simulations. The results indicate that a slight decrease in porosity by 10% (from 90% to 80%) significantly enhances energy absorption and impact resistance while maintaining lightweightfeatures. Significant variations are observed in peak contact force and energy absorption trends. The results demonstrate that single-unit cell rotation improves impact resistance in certain cases, leading to significant enhancements in energy absorption, specific energy absorption, and specific strength, which increased by approximately 18.9% (P90), 17.1% (P90), and 79.5% (P80), respectively, for the dodecahedral (Dodeca)-C structure compared to the original Dodeca-A counterpart at impact of 124 J. In addition, Dodeca-C P80 showed a remarkable 73.1% increase in energy absorption compared to Dodeca-A P80 at a higher impact energy of 248 J. This study provides insights for optimizing porous structures while maintaining consistent unit cell configurations and identical porosity, with rotating unit cell angles enhancing impact resistance.

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