薄壁金属空心球结构压缩力学性能研究

金属空心球结构是一种新型的超轻多孔金属材料。本文对直接堆积和胶合堆积的两球、三球金属空心球列组元进行了单轴准静态压缩实验,分析压缩过程的变形情况,得出其应力/屈曲极限、有效弹性模量、有效应力-应变曲线,并讨论了发生屈服/屈曲的原因。基于实验现象作者提出了三种边界条件,通过分析的方法导出列组元的有效弹性模量公式,其预测值与实验结果较为符合。通过对两种不同堆积模式面组元的压缩实验,研究了金属空心球结构的力学性能和垮塌规律,分析其比刚度和比体积能量吸收值,讨论了两种不同堆积模式的面组元的特点和优越性,发现HC堆积模式具有更好的力学性能。同时对比三球列组元的有效弹性模量发现,SC堆积模式的有效弹性模量只与堆积层数有关。

Study of Mechanical Properties of Thin-Walled MHSS under Compression

Metallic hollow sphere structure (MHSS) is a new type of super-light cellular metallic material. Quasi-static uniaxial compression experiment for sphere array components composed of two or three metallic hollow spheres packed or glued together was conducted. Structure deformation in compression process was observed and analyzed and the yield stress/buckling limit, effective elastic modulus and effective stress-strain curve were obtained respectively. The reason for yield/buckling occurrence was discussed. Three types of boundary conditions were put forward based on experimental phenomenon; the formula of effective elastic modulus was derived analytically, its prediction is basically consistent with experimental data. The mechanical properties and buckling patterns were studied for two types of MHSS face components. Its specific stiffness and specific energy absorption were analyzed. Deformation characteristics and advantages of two types of face components were discussed. It is found that HC packing type has better mechanical properties than that of SC packing type. In addition, effective elastic modulus of SC packing type is contrasted for three sphere arrays. It is found that the effective elastic modulus is just connected with packing accumulation layers.