Theoretical model of effective elastic moduli of composites considering the inclusion features

Abstract

Quantifying the effect of composition on the two-phase composite’s mechanical properties is crucial for the life prediction and durability design of the whole structure. Features of inclusions, especially shape and size, affect the two-phase composites’ effective elastic moduli significantly. However, previous studies have not considered the coupling effects of the inclusion shape, size, and volume fraction. To address this problem, a new normalized theoretical model (modified three-point approximation TPA) is proposed to predict the coupling effects of these factors by introducing two parameters: sphericity and skewness. Then, this work considers the two-phase composite containing inclusions (non-spherical particles of different shapes) and the matrix. The non-spherical particle packing structures are created by the discrete element method. Based on the particulate structures, the reliability of the proposed modified TPA can be verified by the numerical simulation using the lattice model. The correction parameters for sphericity and skewness are 1.21 and −0.58, respectively. The new modified TPA demonstrates that the elastic moduli increase when the number of smaller particles decreases and the particle shape approaches the sphere. The newly proposed modified TPA is significant for designing and applying particulate composites.

Keywords

• Three-point approximation
• Effective elastic moduli
• n-point correlation function
• Two-phase composites
• Inclusion
• Lattice model