Abstract A multiscale approach that couples molecular dynamics (MD) and peridynamics (PD) simulations was implemented to study the mechanical behavior of geopolymer composites (GC) consisting of geopolymer binder (GB), calcium silicate hydrate (CSH) and quartz. Using MD, intrinsic mechanical properties such as bulk modulus, shear modulus and strain energy release rates were determined for the constituent phases as well as the respective two-phase systems. The MD generated properties were then used to determine the input parameters for PD simulations. Both bond-based and state-based PD models were considered for simulating the GC. The first part of the PD study consisted of characterizing the properties of mesoscale porous GB. Interestingly, the predicted modulus of porous GB at porosities corresponding to experimental values compared well with experimental observations based on nanoindentation (NI). NI tests were also conducted using PD simulation to predict the hardness of GB, which was also consistent with experimental data. Finally, PD simulations of mesoscale GC consisting of multiple GB, CSH and quartz (010) domains showed that the presence of quartz (010) increases its strength. It was also observed that the strength of GC increased with increasing domain-sizes of the constituent phases, which can be compared to inverse Hall-Petch effects in nano-crystalline materials.

中文翻译：

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从原子尺度到中尺度：使用分子动力学和近场动力学模拟表征地质聚合物复合材料

摘要 采用结合分子动力学 (MD) 和近场动力学 (PD) 模拟的多尺度方法来研究由地质聚合物粘合剂 (GB)、水合硅酸钙 (CSH) 和石英组成的地质聚合物复合材料 (GC) 的力学行为。使用 MD，确定了组成相以及各自的两相系统的固有机械性能，例如体积模量、剪切模量和应变能释放率。然后使用 MD 生成的属性来确定 PD 模拟的输入参数。基于债券和基于状态的 PD 模型都被考虑用于模拟 GC。PD 研究的第一部分包括表征中尺度多孔 GB 的特性。有趣的是，对应于实验值的孔隙率下多孔 GB 的预测模量与基于纳米压痕 (NI) 的实验观察结果相比较。NI测试也使用PD模拟来预测GB的硬度，这也与实验数据一致。最后，由多个 GB、CSH 和石英 (010) 域组成的中尺度 GC 的 PD 模拟表明，石英 (010) 的存在增加了其强度。还观察到 GC 的强度随着组成相的域尺寸的增加而增加，这可以与纳米晶体材料中的反向霍尔-佩奇效应进行比较。由多个 GB、CSH 和石英 (010) 域组成的中尺度 GC 的 PD 模拟表明，石英 (010) 的存在增加了其强度。还观察到 GC 的强度随着组成相的域尺寸的增加而增加，这可以与纳米晶体材料中的逆霍尔-佩奇效应进行比较。由多个 GB、CSH 和石英 (010) 域组成的中尺度 GC 的 PD 模拟表明，石英 (010) 的存在增加了其强度。还观察到 GC 的强度随着组成相的域尺寸的增加而增加，这可以与纳米晶体材料中的反向霍尔-佩奇效应进行比较。