International Journal of Damage Mechanics, special issue on "Microstructural Mechanics and Damage Mechanics of Materials," Vol. 15, No. 3, pp. 267-288, 2006
G.H. Paulino, H.M. Yin
Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Laboratory, 205 North Mathews Avenue, IL 61801, USA
L.Z. Sun
Department of Civil and Environmental Engineering and Center for Computer-Aided Design, The University of Iowa, Iowa City, IA 52242, USA
Abstract
A micromechanical damage model is developed for two-phase functionally graded materials (FGMs) considering the interfacial debonding of particles and pair-wise interactions between particles. Given an applied mechanical loading on the upper and lower boundaries of an FGM, in the particle-matrix zones, interactions from all other particles over the representative volume element (RVE) are integrated to calculate the homogenized elastic fields. A transition function is constructed to solve the elastic field in the transition zone. The progressive damage process is dependent on the applied loading and is represented by the debonding angles which are obtained from the relation between the particle stress and the interfacial strength. In terms of the elastic equivalency, debonded, isotropic particles are replaced by the perfectly bonded, orthotropic particles. Correspondingly, the effective elasticity distribution in the gradation direction is solved. The computational implementation is disscussed and numerical simulations are provided to illustrate the capability of the proposed model.
KEY WORDS: functionally graded materials (FGMs), micromechanical modeling, damage mechanics, interfacial debonding, pair-wise particle interaction.