Bamboo has been widely used in construction for its high strength, lightweight, and low cost. It usually fails from the skin because of macroscopic fiber splitting. Previous research focused on the strength of bamboo at a structural scale without insight into its chemistry and microstructure of the skin and how they relate to its fracture. In this research, we combine multiscale computational modeling with experimental methods to characterize the distribution of silica particles within the bamboo skin and investigate their effect on fracture. We use a microscope to characterize the chemical and microscopic features of bamboo skin and notice silica particles generally distributed in bamboo skin and their pairwise distances follow a normal distribution. We use molecular dynamics simulations and finite element analysis to investigate the effect of silica particles and their unique distribution on the fracture of bamboo skin. It is noted that the silica forms a perfect bonding interface to cellulose fibers and the particles significantly increase the critical stress up to 6.28% than pure cellulose matrix for cracks that randomly occur. We find that such an enhancement in critical stress against random cracks is only guaranteed by the distribution of silica particles in bamboo skin, as such an enhancement is not observed for other randomly assigned silica particles, suggesting that the silica distribution in bamboo skin is optimal for critical stress improvement for random cracks. This research output can inspire the development of more durable and sustainable bamboo products as well as innovative synthetic composite materials.

竹材因其强度高、重量轻、成本低而被广泛应用于建筑。由于宏观纤维分裂，它通常从皮肤上失败。先前的研究集中在结构尺度上竹子的强度，而没有深入了解其皮肤的化学和微观结构以及它们与断裂的关系。在这项研究中，我们将多尺度计算模型与实验方法相结合，以表征竹皮内二氧化硅颗粒的分布，并研究它们对断裂的影响。我们使用显微镜来表征竹皮的化学和微观特征，并注意到通常分布在竹皮中的二氧化硅颗粒，它们的成对距离遵循正态分布。我们使用分子动力学模拟和有限元分析来研究二氧化硅颗粒及其独特分布对竹皮断裂的影响。值得注意的是，二氧化硅与纤维素纤维形成了完美的粘合界面，对于随机出现的裂纹，颗粒比纯纤维素基质显着增加了高达 6.28% 的临界应力。我们发现，这种对随机裂纹的临界应力的增强只能通过竹皮中二氧化硅颗粒的分布来保证，而对于其他随机分配的二氧化硅颗粒则没有观察到这种增强，这表明竹皮中的二氧化硅分布是最佳的随机裂纹的临界应力改进。