Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling
Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling
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两相和混合纳米复合材料机械性能的测定：实验测定和多尺度建模
DOI：
10.1515/polyeng-2020-0312
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发表时间：
2021
影响因子：
2
通讯作者：
F. Aghadavoudi
中科院分区：
文献类型：
--
作者：
M. Haghighi;H. Golestanian;F. Aghadavoudi
本文通过实验研究了填料含量和杂化纳米填料的使用对纳米复合材料的团聚和弹性模数、极限强度、断裂伸长率等力学性能的影响。此外，还利用多尺度建模技术对热固性环氧基两相和混杂纳米复合材料进行了数值模拟。首先，考虑界面相的影响，在纳米尺度上进行分子动力学模拟。其次，采用有限元方法和细观力学建模方法对纳米复合材料进行了微观和宏观建模。制备了含有碳纳米管、石墨烯纳米片和不同填料含量的杂化纳米填料的纳米复合材料样品，并对其进行了测试。此外，场发射扫描电子显微镜也被用来从样品的断口获得显微照片。结果表明，在两相纳米复合材料中，随着增强体质量分数的增加，弹性模量和极限强度增大，而断裂伸长率减小。此外，在两相纳米复合材料中，当纳米填料含量较高时，尤其是高于0.75wt%时，纳米填料会发生团聚。在杂化纳米复合材料样品中观察到纳米填料的团聚要低得多。因此，在填料总含量相同的情况下，使用杂化纳米填料可以延缓/防止团聚并改善纳米复合材料的力学性能。
Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.