Bolan Matthew, Dean Mackenzie, Bardelcik Alexander
School of Engineering, College of Engineering and Physical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Polymers (Basel). 2023 Jan 31;15(3):713. doi: 10.3390/polym15030713.
We investigate the compressive energy absorption performance of polymeric octet-truss lattice structures that are 3D printed using high-resolution stereolithography. These structures are potential candidates for personal protective equipment, structural, and automotive applications. Two polymeric resins (high-strength/low-ductility and moderate-strength/high-ductility) were used in this work, and a comprehensive uniaxial tensile characterization was conducted to establish an optimal UV curing time. The external octet-truss structure geometry (3″ × 3″ × 3″) was maintained, and four different lattice cell densities (strut length, L) and three different strut radii (R) were printed, UV cured, and compression tested. The compressive stress-strain and energy absorption (EA) behavior were quantified, and the EA at 0.5 strain for the least dense and smallest R structure was 0.02 MJ/m, while the highest density structure with the largest R was 1.80 MJ/m for Resin 2. The structural failure modes varied drastically based on resin type, and it was shown that EA and deformation behavior were related to L, R, and the structures' relative density (ρ¯). For the ductile resin, an empirical model was developed to predict the EA vs. compressive strain curves based on L and R. This model can be used to design an octet-truss lattice structure based on the EA requirements of an application.
我们研究了采用高分辨率立体光刻技术3D打印的聚合物八面体桁架晶格结构的压缩能量吸收性能。这些结构是个人防护装备、结构和汽车应用的潜在候选材料。本研究使用了两种聚合物树脂（高强度/低延展性和中等强度/高延展性），并进行了全面的单轴拉伸表征以确定最佳的紫外线固化时间。保持外部八面体桁架结构的几何尺寸（3英寸×3英寸×3英寸），打印、紫外线固化并测试了四种不同的晶格单元密度（支柱长度，L）和三种不同的支柱半径（R）。对压缩应力-应变和能量吸收（EA）行为进行了量化，对于密度最小且半径最小的结构，在0.5应变时的EA为0.02 MJ/m，而对于树脂2，具有最大R的最高密度结构的EA为1.80 MJ/m。结构失效模式因树脂类型而异，结果表明EA和变形行为与L、R以及结构的相对密度（ρ¯）有关。对于韧性树脂，基于L和R建立了一个经验模型来预测EA与压缩应变曲线。该模型可用于根据应用的EA要求设计八面体桁架晶格结构。
