Micromechanical modeling and experimental characterization for the elastoplastic behavior of a functionally graded material

Functionally Graded Materials (FGMs) are characterized by the distribution in composition and structure gradually over volume, which were recently designed and developed as a key component of a multifunctional building envelope for the high performance of energy efficiency. It was realized by mixing aluminum particles and fine High-Density Polyethylene (HDPE) powders through a vibration-sedimentation process. To investigate the elastoplastic behavior of FGMs, an elastoplastic model based on micromechanics with pairwise particle interactions is developed in this study. The particle phase is assumed to remain in its linearly elastic state while the matrix phase undergoes elastoplastic deformation. The corresponding yield function for the FGMs is investigated, where the pairwise interaction and probabilistic spatial distribution of particles are utilized to accommodate the gradation of particle volume fraction. Accordingly, the overall elastoplastic behavior of FGMs is established through the microscopic homogenization. The proposed algorithm is validated with uniaxial compression test of FGM samples, where the authentic particle distribution is captured statistically through image processing method. Finally, the effect of volume fraction distributions on the overall effective elastoplastic behavior of FMGs is investigated. (C) 2020 Elsevier Ltd. All rights reserved.