缝纫泡沫夹芯复合材料细观纤维柱破坏行为

缝纫泡沫夹芯复合材料中的纤维柱在拔出过程中的破坏行为复杂导致结构承载性能难以预测。采用真空辅助树脂注射(VARI)工艺制备了缝纫泡沫夹芯复合材料,并使用层间拉伸试验(ITT)研究了缝纫泡沫夹芯复合材料中含有单根缝线纤维柱细观试件的破坏过程。讨论了不同破坏现象对缝线纤维柱拔出摩擦过程的影响,并分析了缝纫泡沫夹芯复合材料的破坏模式。分析了缝线粗细的变化对试件破坏过程中关键的力、位移等参数及能量吸收性能的影响。研究了由于成型工艺所导致的缺胶现象对缝纫泡沫夹芯复合材料性能的影响。结果表明:缝纫泡沫夹芯复合材料的能量吸收性能、关键位移参数及最大载荷都随着缝线变粗而增大。但是缝纫泡沫夹芯复合材料的破坏模式对其也有一定的影响,导致了变化趋势的波动;缺胶缝纫泡沫夹芯复合材料由于缺陷的存在,最大破坏载荷和能量吸收性能均有所下降。

Fracture behavior of meso-fiber column in the stitched foam sandwich composites

The failure behavior of the single fiber column is complicated during the pull-out process in the stitched foam sandwich composites, so the carrying capacity of the structure can be unpredictable. The stitched foam sandwich composites were manufactured by the vacuum assisted resin injection (VARI) process. The interlaminar tension test (ITT) was employed to investigate the fracture process of the meso-specimen containing a single fiber column in the stitched foam sandwich composites. The effects of different fracture phenomena on the pulling friction process of the fiber column were discussed, and the fracture modes of the resin sufficient specimens were analyzed. The influences of the thread thickness on the key parameters such as force, displacement and energy absorption were studied. The influence of the resin deficiency caused by manufacture process on the performance of the stitched foam sandwich composite was analyzed. The results show that the energy absorption, key displacement parameters and maximum load of the stitched foam sandwich composite present an upward trend with the increase of the stitched thread thickness. However, the failure modes of the stitched foam sandwich composite also have a certain influence on the trend, which leads to the fluctuation of the trend. The energy absorption and maximum load of the resin deficient specimen are decreased due to the existence of defects.