X状Z-pin增强泡沫夹层结构的剪切性能

Shear properties of X-Z-pin reinforced foam core sandwich

通过不同Z-pin角度(15°和25°)和夹芯厚度(8 mm和12.7 mm)的X状Z-pin增强泡沫夹层材料的剪切性能试验,与相同材料同尺寸的未增强件进行对比,考察X状Z-pin对泡沫夹层结构的增强作用。试验结果表明,X状Z-pin增强使材料的剪切强度和刚度都有较大幅度的提高;同时,Z-pin的加入使该结构具有与传统泡沫夹层材料不同的剪切破坏形式。在此基础上,结合空间网架结构和等效夹杂方法,提出了X状Z-pin增强泡沫夹层结构剪切刚度模型,计算结果与试验值符合良好。结果表明,X状Z-pin增强不仅能大幅度提高泡沫夹层结构的剪切性能,并具有良好的可设计性,可以通过改变Z-pin角度和材料等改变其力学性能。

A series experiments were carried out to investigate the responses of X-Z-pinned foam core sandwich materials under shear loading, including inclination angles of 15° and 25° with foam core thickness of 12.7 mm and 8 mm, each group of which had a contrasted one. The experimental results show that the Z-pinned foam core can reinforce the shear modulus and strength of the sandwich markedly. At the same time, the X- Z- pin reinforced material has a special failure pattern which is different from the unreinforced one. On the basis of integrating the space truss frame and equivalent inclusion method, a method for predicting the shear modulus of the composites was established. The theoretical prediction coincides with the experimental data well. In addition, the novel Z- pinned cores are found to exhibit more favorable programmable property than the conventional sandwich cores. Altering the pinned angle and pin materials can ameliorate the mechanical properties of sandwich.