By considering the surface free energy effect, an analytical investigation on the fracture behaviors of nanoparticle-reinforced composites was performed in this study. The plastic zones ahead of the crack tips based on the Irwin model were introduced in our analysis, which has a significant influence on the fracture toughness of inelastic structures, especially for polymer and metal matrix composites. Take copper and aluminum nanoparticles as examples, comprehensive parametric studies were conducted to investigate the interaction between a Griffith crack and the nearby nanoparticle. It was found that for nanoparticles with the radius of less than 10 nm, apart from the mechanical property of the nanoparticle, the surface free energy effect plays a dominant role in determining the fracture behaviors of the nanoparticle-reinforced composites. Moreover, taking the surface free energy into account, a decrease in the plastic zone size is obtained, particularly for the crack tip nearer the nanoparticle.

通过考虑表面自由能效应，本研究对纳米颗粒增强复合材料的断裂行为进行了分析研究。在我们的分析中引入了基于 Irwin 模型的裂纹尖端之前的塑性区，这对非弹性结构的断裂韧性有显着影响，特别是对于聚合物和金属基复合材料。以铜和铝纳米粒子为例，进行了全面的参数研究，以研究格里菲斯裂纹与附近纳米粒子之间的相互作用。发现对于半径小于10 nm的纳米粒子，除了纳米粒子的力学性能外，表面自由能效应在决定纳米粒子增强复合材料的断裂行为中起主导作用。