Elastic moduli of particulate composites with graded filler-matrix interfaces

摘要

The elastic response of plane-array models of composites reinforced by particles or aligned fibers having graded interfaces with the matrix is analyzed.Such microstructure is representative of a new class of polymer matrix composite materials in which the filler is nanometer-sized.In such materials,the polymer chains in thematrix are preferentially oriented close to the interface with the relativley rigid fillers,this leading to a graded interfacial layer about eachinclusion.The composite elastic moduli are determined basedon the properties and geometry of the interfacial graded alyewr as well as on the moduli of the filler and the matrix,and the volume fraction of filler.Conversion curves are constructed allowing for an equivalence to be established betweent he present case and that of similar composites without graded interfaces.Based on these conversion curves,standard homogenization algorithms can be applied to determine the overall elastic properties of such composite.The fillers are considered to be stiffer than the matrix,both rigid and of finite stiffness. Results for both sliding and bonde dinterfaces are presented.The effect of anisotropic material properties in the graded regon on the composite moduli is also investigated.The results of themodel are compared with published experimental data.