Ghosh Mahan, D'Souza Nandika Anne
Mechanical Engineering, University of North Texas, 1155 Union Circle #310440, Denton, TX 76203-5017, USA.
Materials Science and Engineering, University of North Texas, 1155 Union Circle #310440, Denton, TX 76203-5017, USA.
Polymers (Basel). 2024 May 9;16(10):1340. doi: 10.3390/polym16101340.
The utilization of lattice-type cellular architectures has seen a significant increase, owing to their predictable shape and the ability to fabricate templated porous materials through low-cost 3D-printing methods. Frames based on atomic lattice structures such as face-centered cubic (FCC), body-centered cubic (BCC), or simple cubic (SC) have been utilized. In FDM, the mechanical performance has been impeded by stress concentration at the nodes and melt-solidification interfaces arising from layer-by-layer deposition. Adding plates to the frames has resulted in improvements with a concurrent increase in weight and hot-pocket-induced dimensional impact in the closed cells formed. In this paper, we explore compressive performance from the partial addition of plates to the frames of a SC-BCC lattice. Compression testing of both single unit cells and 4 × 4 × 4 lattices in all three axial directions is conducted to examine stress transfer to the nearest neighbor and assess scale-up stress transfer. Our findings reveal that hybrid lattice structure unit cells exhibit significantly improved modulus in the range of 125% to 393%, specific modulus in the range of 13% to 120%, and energy absorption in the range of 17% to 395% over the open lattice. The scaled-up lattice modulus increased by 8% to 400%, specific modulus by 2% to 107%, and energy absorption by 37% to 553% over the lattice frame. Parameters that emerged as key to improved lightweighting.
由于其可预测的形状以及能够通过低成本的3D打印方法制造模板化多孔材料，晶格型蜂窝结构的应用显著增加。基于面心立方（FCC）、体心立方（BCC）或简单立方（SC）等原子晶格结构的框架已被采用。在熔融沉积成型（FDM）中，逐层沉积导致的节点和熔固界面处的应力集中阻碍了机械性能。在框架上添加板材虽有改善，但同时增加了重量，并对形成的封闭单元中的热口袋产生尺寸影响。在本文中，我们探索了通过向SC - BCC晶格框架部分添加板材来提高压缩性能。对单个晶胞和4×4×4晶格在所有三个轴向方向上进行压缩测试，以检查应力向最近邻的传递并评估放大后的应力传递。我们的研究结果表明，与开放晶格相比，混合晶格结构的晶胞在模量方面显著提高了125%至393%，比模量提高了13%至120%，能量吸收提高了17%至395%。与晶格框架相比，放大后的晶格模量提高了8%至400%，比模量提高了2%至107%，能量吸收提高了37%至553%。这些参数成为改善轻量化的关键因素。
