Elastodynamic analysis of aligned particulate composites with the inclusion-based boundary element method (iBEM)

This paper extends the inclusion-based boundary element method (iBEM) to conduct elastodynamic analysis of chain-structured composites with aligned spherical inhomogeneities and predict the effective material properties depending on the frequency and specimen-particle size ratio (SPR). The iBEM algorithm utilizes boundary integral equations to handle the boundary conditions of the specimen. Using Eshelby’s equivalent inclusion method (EIM), the inhomogeneities are simulated as the matrix by introducing continuously distributed eigen-fields, where eigenstrain and eigen-body-force are introduced to simulate stiffness and density mismatches, respectively. The polynomial-form eigen-fields are evaluated through closed-form domain integrals of the fundamental solution. The local solutions are verified by the finite element analysis, and the overall material behavior is determined by eigen-fields. The results of virtual experiments with three SPRs show that conventional micromechanical models cannot accurately predict the elastodynamical behavior of the composites due to the boundary effects and actual microstructure. In addition, numerical case studies of a representative composite sample at different excitation frequencies show that the elastodynamic energy is significantly different even when the same loading magnitude is applied. Therefore, it is necessary to conduct the cross-scale modeling with the actual microstructure, and the iBEM provides high fidelity results.