In-Plane mechanical and failure responses of honeycombs with syntactic foam cell walls
In-Plane mechanical and failure responses of honeycombs with syntactic foam cell walls
复制标题
DOI：
10.1016/j.compstruct.2022.115866
复制
发表时间：
2022-09-01
影响因子：
6.3
通讯作者：
Koohbor, Behrad
中科院分区：
文献类型：
--
作者：
Pagliocca, Nicholas;Youssef, George;Koohbor, Behrad
这项工作研究了具有复合细胞壁和细胞密度空间梯度的六边形蜂窝的承载和能量吸收能力。通过改变中空微球（微球）的体积分数、细胞壁厚度和细胞密度的空间梯度来处理结构和性能调整。结构的机械行为通过使其受到面内压缩来表征。这些结构在细观和宏观尺度上的全场变形和失效响应分别通过数字图像相关（DIC）和事后断裂分析来表征。介观尺度分析揭示了细胞铰链处的异质应变积累，这导致铰链附近的断裂。所有样品中失效的特征都是脆性模式。结果表明，通过在空间上受控地将微球合并到细胞支柱中，可以提高结构的能量吸收能力，但会降低整体强度。此外，与均匀密度结构相比，细胞密度分级显着提高了能量吸收性能，并提供了降低结构密度同时实现高机械性能的机制。
This work investigates the load-bearing and energy absorption capacities of hexagonal honeycombs with syntactic cell walls and spatial gradation of cell densities. Structures are processed and property-tuned by varying the volume fraction of hollow microspheres (microballoons), cell wall thickness, and spatial gradation of cell densities. The mechanical behavior of the structures is characterized by subjecting them to in-plane compression. Full-field deformation and failure responses of these structures at meso- and macro-scales are characterized by digital image correlation (DIC) and postmortem fracture analyses, respectively. Mesoscale analyses reveal heterogeneous strain accumulation at the cell hinges, which leads to a fracture in the vicinity of the hinge. Failure is characterized by a brittle mode in all samples. It is shown that the energy absorption capacity of the structures can be improved with the spatially-controlled incorporation of microballoons into the cell struts, at the penalty of reduced overall strength. In addition, cell-density gradation offers a notable improvement to the energy absorption performance over uniform density structures and a mechanism to lower structural density while achieving high mechanical performance.