阻塞状态下的非球体颗粒材料优化设计研究

A particulate system in the jamming state of disordered packing is mechanically stable and has lower packing densities comparing to ordered packings. Such systems can construct light and material saving structures which also have the ability to bear loads. Moreover, particulate systems transfer between solid and liquid phases by jamming transition. Such systems have the ability of boundary adaptation as well as bearing loads. These properties present a broad application prospect for jammed particles in material design. The project will investigate the influence of the particle shape and size distribution in the maximally random jammed state, as well as the order degree in particulate systems on the mechanical properties of granular materials. The evolution method of the configuration of granular materials for the optimization of mechanical properties will also be studied, and an optimal design system for granular materials of nonspherical particles will be established. Mechanical experiments will be carried out to verify the effectivity of the design system.

无序填充的阻塞状态颗粒材料具有力学稳定性并且有较低的填充密度，适合构成能承受一定载荷的轻质、省材料结构。此外，阻塞转变可以使颗粒材料在流体和固体形态间转换，使结构在承力的同时能够自适应边界形状。这些特性使其在材料设计中具有广阔的应用前景。本项目将研究最大随机阻塞状态下颗粒形状和粒径分布以及颗粒体系的有序程度对颗粒材料力学性能的影响，研究以力学性能为导向的颗粒材料结构演化设计方法，建立非球体颗粒材料的优化设计系统，并开展颗粒材料力学实验来验证设计方法的有效性。

无序填充的阻塞状态颗粒材料具有力学稳定性并且有较低的填充密度，适合构成能承受一定载荷的轻质、省材料结构。此外，阻塞转变可以使颗粒材料在流体和固体形态间转换，使结构在承力的同时能够自适应边界形状。这些特性使其在材料设计中具有广阔的应用前景。本项目研究了最随机阻塞状态下颗粒形状和大小对填充的刚度和稳定性等力学性能的影响，发现填充率与力学性能高度相关，而颗粒形状和大小对力学性能的影响与对填充率的影响十分类似。为此，本项目给出了考虑颗粒大小和形状两种因数耦合的填充率预测经验公式。本项目还研究了填充密度和有序程度对填充率等填充性质的影响，发现填充率峰值位置与填充结构的有序程度有关而与填充方法和填充率的高低无关。本项目发展了一套基于遗传算法的颗粒形状演化设计方法，可用于给定物理和力学条件下的颗粒外形设计。本项目的研究加深了对颗粒无序填充物理和力学特性的认识，其研究成果还将对工程轻质材料设计起指导作用。