TY - EJOU AU - Takashima, Shuji AU - Nakagaki, Michihiko AU - Miyazaki, Noriyuki TI - An Elastic-Plastic Constitutive Equation Taking Account of Particle Size and Its Application to A Homogenized Finite Element Analysis of A Composite Material T2 - Computer Modeling in Engineering \& Sciences PY - 2007 VL - 20 IS - 3 SN - 1526-1506 AB - Composite materials have complicated microstructures. These microstructures affect the macroscopic deformation of composite materials. In the present study, we focus on the effect of particle size in a particle-dispersed composite material on the mechanical strength of the material. For this purpose, we derived a macroscopic elastic-plastic constitutive equation using a modified version of the Eshelby's equivalent inclusion method combined with the gradient plasticity. We incorporated this macroscopic elastic-plastic constitutive equation into a finite element program and performed a homogenized finite element analysis of a particle-dispersed composite material in which both the macroscopic and microscopic behaviors of the composite material were obtained. The present method successfully revealed the size effect in a particle-dispersed composite material, namely that its mechanical strength increases with a decrease in the particle size. KW - size effect KW - composite material KW - Eshelby's theory KW - gradient plasticity DO - 10.3970/cmes.2007.020.193