Using a multiscale modeling framework that combines molecular dynamics (MD) simulation and micromechanics-based homogenization method, the effective elastic properties of polymer-matrix nanocomposites are predicted for a wide range of interfacial bond stiffness (energy). We consider the homogenization method with two interface models, the interface spring model and interphase model, to account for the interfacial effect, and test the validity of both models by comparing them to the finite element analyses. We then calculate the bulk moduli of Nylon6 (matrix)–SiC (nanoparticle) nanocomposite using MD simulations by varying the interfacial bond stiffness and size of the SiC nanoparticle. By comparing the bulk moduli from MD simulations with the theoretical predictions from the homogenization method, we find the interfacial bond stiffness range within which each interfacial model is relevant. We also investigate and explain the effect of particle size on the effective material properties at different interfacial bond stiffnesses. The effect of interphase and interfacial imperfection (damage) observed from the MD simulation on the effective properties are analyzed. Finally, we predict the effective properties of the Nylon6-SiC nanocomposite by varying the level of SiC particle agglomeration and study how the effect of agglomeration changes over the interfacial bond stiffness.

使用结合分子动力学 (MD) 模拟和基于微观力学的均质化方法的多尺度建模框架，可以预测聚合物基质纳米复合材料的有效弹性特性，以适应广泛的界面结合刚度（能量）。我们考虑使用两个界面模型（界面弹簧模型和界面模型）的均质化方法来解释界面效应，并通过将它们与有限元分析进行比较来测试这两种模型的有效性。然后，我们通过改变 SiC 纳米颗粒的界面结合刚度和尺寸，使用 MD 模拟计算 Nylon6（基质）-SiC（纳米颗粒）纳米复合材料的体积模量。通过将 MD 模拟的体积模量与均质化方法的理论预测进行比较，我们找到了每个界面模型相关的界面结合刚度范围。我们还研究并解释了粒径对不同界面结合刚度下有效材料性能的影响。分析了从 MD 模拟中观察到的界面和界面缺陷（损坏）对有效性能的影响。最后，我们通过改变 SiC 颗粒团聚的水平来预测 Nylon6-SiC 纳米复合材料的有效性能，并研究团聚对界面结合刚度的影响如何变化。分析了从 MD 模拟中观察到的界面和界面缺陷（损坏）对有效性能的影响。最后，我们通过改变 SiC 颗粒团聚的水平来预测 Nylon6-SiC 纳米复合材料的有效性能，并研究团聚对界面结合刚度的影响如何变化。分析了从 MD 模拟中观察到的界面和界面缺陷（损坏）对有效性能的影响。最后，我们通过改变 SiC 颗粒团聚的水平来预测 Nylon6-SiC 纳米复合材料的有效性能，并研究团聚对界面结合刚度的影响如何变化。