开孔空心球结构的准静态压缩力学行为

Quasi-static Compressive Mechanical Behaviors of Perforated Hollow-Sphere Structures

空心球材料具有超轻、高比强度、缓冲性能好等优点,在航空航天、汽车安全等领域具有诸多需求,其力学性能主要受微观结构的影响。利用实验和有限元数值模拟研究3D打印开孔空心球结构的准静态压缩力学行为,主要分析胞元个数、开孔孔径以及空心球排列方式对两种连接方式空心球结构力学性能的影响。研究结果证实,开孔空心球结构的准静态压溃过程主要分为弹性变形阶段、塑性大变形阶段以及密实化阶段;当试件中胞元个数达到3×3×3以上时,其力学性能基本与胞元个数无关;总体上,有连接颈结构的比模量和比强度高于无连接颈结构,而无连接颈结构的比吸能高于有连接颈结构;面心立方排列结构的压缩力学性能优越,其次是体心立方排列结构,简单立方排列结构力学性能最弱;简单立方和体心立方结构的比模量、比强度以及比吸能与孔径之间是线性关系,而对于面心立方结构是非线性关系。为3D打印空心球材料的设计与应用提供一定参考。

Due to the advantages of ultra-light, high specific strength and good cushioning performance, hollowsphere materials have a large demand in the fields of aerospace, automobile safety and so on. Its mechanical properties are mainly affected by the microstructure. Quasi-static compressive properties of 3D printed hollowsphere structures with perforations were investigated experimentally and numerically. The effects of cell number,hole diameter and spheres packing pattern on the mechanical properties of structures with two connections were mainly analyzed. The results confirm that the deformation process of perforated hollow-sphere structures includes the linear elastic stage, large plastic deformation stage and densification stage;when the number of cells in the structure reaches 3×3×3, the mechanical properties are basically independent of the cell number;in general, the specific modulus and strength of the structure having connection necks are larger than those of the structure having no connection neck, while the specific energy absorption of the structure having no connection neck is larger than that of the structure having connection necks;The compressive performance of face centered cubic(FCC) structure is superior, followed by body centered cubic(BCC) structure, and the performance of simple cubic(SC) structure is the weakest;the specific modulus, specific strength and specific energy absorption of simple cubic and body centered cubic structures are linear with the hole diameter, and nonlinear for face centered cubic structures. It provides a reference for hollow sphere materials design and applications.