为提高对以木纤维为填充材料的复合材料的理解和性能分析,对木质纳米纤维素中的非晶态结构进行分子建模与拉伸变形仿真研究.通过对纳米纤维素非晶态结构进行周期性边界条件建模,在能量最小化和热平衡后,基于ReaxFF力场用开源代码程序LAMMPS对模型进行拉伸变形仿真,模拟原子间的相互作用,对其数据结果采用MATLAB进行后处理分析,并采用可视化开源软件Atomeye对变形过程进行监控.通过所建模型仿真研究数据,可以计算得到木质纳米纤维素纳观尺度的机械特性,求得纳观结构中应力一应变曲线,将其同实验数据相比较,用于预测材料宏观尺度各特性以及本构关系.该研究为今后分析高分子聚合物和纤维素的纳米微观界面相容性打下基础,能更好地理解高分子纤维聚合材料的力学性能.%The research objective is to gain a better fundamental understanding of the mechanical behavior of cellulose structure in wood microfiber for enhancing the mechanical properties of ceIIulosic-based composites. Molecular static and molecular dynamics simulations were used to both generate and deform the amorphous cellulose structure in a three-dimensional periodic simulation cell. The 14-p-D-glucose structure was chosen along with a reactive force field, ReaxFF, to model the atomic interactions and complex bonding of cellulose. Mechanical properties were calculated for these models, and the predicted geometric, energetic and elastic material properties were compared to the published modeling results and experimental measurements. The significance of the research is that this sets the stage for future polymer-cellulose predictive microme-chanical models. These predictive models can be used to elucidate the interfacial compatibility between the cellulose and polymer, which is helpful in understanding how deposited nanoparticles and nanophases on cellulose surfaces affect this interfacial strength.
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