中空纳米微球填充复合材料的有效力学性能

EFFECTIVE MECHANICAL PROPERTIES OF SOLID FILLED BY HOLLOW NANOSPHERES

中空纳米微球可作为复合材料填充体使用.与相同粒径下的实心纳米颗粒相比,中空纳米微球密度更低,存在表/界面应力效应的面积更大,由此导致的不同力学行为值得人们关注和研究.目的是研究表/界面应力对中空纳米微球填充复合材料力学行为的影响.首先,基于广义自洽原理,利用考虑表/界面应力影响的四相球模型导出了中空纳米微球填充复合材料在单向载荷作用下的弹性场,获得了纳米复合材料有效弹性模量的闭合形式解.然后,分析了纳米复合材料存在的尺度相关性.算例结果表明,有效弹性常数和环向应力与经典解答不同,取决于表/界面性能、纳米中空微球粒径和壁厚.该结论对于中空纳米微球复合材料具有指导意义.

The hollow nanospheres with scientific and technological interest can be used as fillers in preparation of composite materials. In general, hollow nanospheres have more significant surface effect in filled materials than solid nanoparticles. The objective of this paper is to research the influence of surface/interface stress on the mechanical behavior of solid containing hollow nanospheres. Based on the generalized self-consistent principle, a four phase model incorporating surface/interface stress effect is developed to derive the elastic fields of the solid under uniaxial loading and to obtain the closed-form solutions for the effective elastic constants of the solid. In addition, the size dependence of nanocomposites is also analyzed. The numerical results show the difference from the classical results of the effective elastic constants and the circumferential stress. Furthermore, the effective mechanical properties of the solid are dependent on the volume fraction, the surface/interface properties, the outer radius and the wall thickness of the hollow nanosphere. The results of this paper are helpful to fabricate the composite materials with hollow nanospheres.